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Adaptation	A trait that helps a living thing survive		animal-adaptations-habitats
Habitat	The natural home of a plant or animal		animal-adaptations-habitats
Camouflage	Coloring that helps an animal blend in		animal-adaptations-habitats
Mimicry	When one species looks like another to stay safe		animal-adaptations-habitats
Hibernation	A deep sleep through winter to save energy		animal-adaptations-habitats
Migration	Traveling to another place for food, warmth or breeding		animal-adaptations-habitats
Nocturnal	Active at night		animal-adaptations-habitats
Diurnal	Active during the day		animal-adaptations-habitats
Crepuscular	Active at dawn and dusk		animal-adaptations-habitats
Warning coloration	Bright colors that tell predators an animal is harmful, like a poison dart frog		animal-adaptations-habitats
Which animal changes color to match its surroundings?	The chameleon		animal-adaptations-habitats
Which animal can drop its tail to escape a predator?	A lizard		animal-adaptations-habitats
Why do polar bears have thick fur and blubber?	To stay warm in cold Arctic weather		animal-adaptations-habitats
Why does an Arctic hare turn white in winter?	To blend in with snow		animal-adaptations-habitats
How does a camel survive in a desert?	It stores fat in its hump and can go a long time without water		animal-adaptations-habitats
What do a camel's wide feet do?	Keep it from sinking in sand		animal-adaptations-habitats
How does a cactus store water?	In its thick stem		animal-adaptations-habitats
How do owls hunt in the dark?	Large eyes, sharp hearing and silent flight		animal-adaptations-habitats
How do bats find food in the dark?	Echolocation		animal-adaptations-habitats
Why do cheetahs have long legs?	To run very fast		animal-adaptations-habitats
Why do giraffes have long necks?	To reach leaves high in trees		animal-adaptations-habitats
What is an elephant's trunk used for?	Breathing, smelling, drinking and grabbing things		animal-adaptations-habitats
Why do ducks have webbed feet?	To swim well		animal-adaptations-habitats
Why do woodpeckers have strong beaks?	To peck into trees for insects		animal-adaptations-habitats
Why do hummingbirds have long thin beaks?	To drink nectar from flowers		animal-adaptations-habitats
Why do eagles have sharp talons?	To catch and hold prey		animal-adaptations-habitats
Why do fish have gills?	To take oxygen from water		animal-adaptations-habitats
Why do whales have blubber?	To stay warm in cold water		animal-adaptations-habitats
Why do skunks spray?	To scare away predators		animal-adaptations-habitats
Why do porcupines have quills?	To protect themselves		animal-adaptations-habitats
Why do turtles have shells?	For protection		animal-adaptations-habitats
What does an octopus do to escape danger?	Squirts ink and changes color		animal-adaptations-habitats
How does a snake sense prey?	By smelling with its tongue		animal-adaptations-habitats
How do penguins keep warm?	Thick feathers and a layer of fat; they huddle together		animal-adaptations-habitats
How does a frog catch insects?	With a long sticky tongue		animal-adaptations-habitats
What is a spider's web for?	Catching prey		animal-adaptations-habitats
How do bees help plants?	They carry pollen between flowers		animal-adaptations-habitats
Why do beavers have flat tails?	To steer when swimming and slap warnings		animal-adaptations-habitats
Why do seals have flippers?	To swim		animal-adaptations-habitats
How do arctic foxes stay warm?	Thick fur and small ears		animal-adaptations-habitats
Why do desert foxes have big ears?	To release heat		animal-adaptations-habitats
How do monarch butterflies survive winter?	They migrate to warmer places		animal-adaptations-habitats
Where do salmon go to lay eggs?	Back up rivers where they were born		animal-adaptations-habitats
Where do Arctic terns migrate?	From the Arctic to the Antarctic and back, a very long trip		animal-adaptations-habitats
What do gray whales do each year?	Migrate between cold feeding waters and warm breeding lagoons		animal-adaptations-habitats
Ocean habitat	Salt water home for fish, whales and more		animal-adaptations-habitats
Desert habitat	Dry land with little rain, like the Sahara		animal-adaptations-habitats
Rainforest habitat	Warm, wet forest with many species		animal-adaptations-habitats
Grassland habitat	Open land covered with grasses		animal-adaptations-habitats
Arctic habitat	The cold region around the North Pole		animal-adaptations-habitats
Wetland habitat	Land with shallow water like marshes		animal-adaptations-habitats
Pond habitat	Small body of still fresh water		animal-adaptations-habitats
Coral reef habitat	Warm shallow seas with coral		animal-adaptations-habitats
Mountain habitat	High, cold, windy land		animal-adaptations-habitats
Cave habitat	Dark underground home for bats and blind fish		animal-adaptations-habitats
Deep-sea adaptation: bioluminescence	Making light to find food or mates		animal-adaptations-habitats
Anglerfish	A deep-sea fish with a glowing lure		animal-adaptations-habitats
Symbiosis example: clownfish and anemone	The clownfish is protected by the anemone and cleans it		animal-adaptations-habitats
Instinct	Behavior an animal is born knowing		animal-adaptations-habitats
Learned behavior	Something an animal learns, like a dog sitting on command		animal-adaptations-habitats
Baby cat	Kitten		animal-babies-and-homes
Baby dog	Puppy		animal-babies-and-homes
Baby cow	Calf		animal-babies-and-homes
Baby horse	Foal		animal-babies-and-homes
Baby sheep	Lamb		animal-babies-and-homes
Baby goat	Kid		animal-babies-and-homes
Baby pig	Piglet		animal-babies-and-homes
Baby chicken	Chick		animal-babies-and-homes
Baby duck	Duckling		animal-babies-and-homes
Baby goose	Gosling		animal-babies-and-homes
Baby swan	Cygnet		animal-babies-and-homes
Baby frog	Tadpole		animal-babies-and-homes
Baby kangaroo	Joey		animal-babies-and-homes
Baby bear	Cub		animal-babies-and-homes
Baby lion	Cub		animal-babies-and-homes
Baby fox	Kit or cub		animal-babies-and-homes
Baby wolf	Pup		animal-babies-and-homes
Baby seal	Pup		animal-babies-and-homes
Baby deer	Fawn		animal-babies-and-homes
Baby rabbit	Kit or bunny		animal-babies-and-homes
Baby owl	Owlet		animal-babies-and-homes
Baby eagle	Eaglet		animal-babies-and-homes
Baby elephant	Calf		animal-babies-and-homes
Baby giraffe	Calf		animal-babies-and-homes
Baby whale	Calf		animal-babies-and-homes
Baby dolphin	Calf		animal-babies-and-homes
Baby fish	Fry		animal-babies-and-homes
Baby insect (like a butterfly) after the egg	Larva		animal-babies-and-homes
Baby butterfly stage	Caterpillar		animal-babies-and-homes
Baby bat	Pup		animal-babies-and-homes
Baby turtle	Hatchling		animal-babies-and-homes
Baby crocodile	Hatchling		animal-babies-and-homes
Baby penguin	Chick		animal-babies-and-homes
Baby hippo	Calf		animal-babies-and-homes
Baby spider	Spiderling		animal-babies-and-homes
Baby pigeon	Squab		animal-babies-and-homes
Male chicken	Rooster		animal-babies-and-homes
Female chicken	Hen		animal-babies-and-homes
Male cow	Bull		animal-babies-and-homes
Female cow	Cow		animal-babies-and-homes
Male horse	Stallion		animal-babies-and-homes
Female horse	Mare		animal-babies-and-homes
Male sheep	Ram		animal-babies-and-homes
Female sheep	Ewe		animal-babies-and-homes
Male pig	Boar		animal-babies-and-homes
Female pig	Sow		animal-babies-and-homes
Male duck	Drake		animal-babies-and-homes
Female duck	Duck		animal-babies-and-homes
Male goose	Gander		animal-babies-and-homes
Male deer	Buck or stag		animal-babies-and-homes
Female deer	Doe		animal-babies-and-homes
Female lion	Lioness		animal-babies-and-homes
Male peafowl	Peacock		animal-babies-and-homes
Female peafowl	Peahen		animal-babies-and-homes
Male goat	Billy or buck		animal-babies-and-homes
Female goat	Nanny or doe		animal-babies-and-homes
Male fox	Dog or tod		animal-babies-and-homes
Female fox	Vixen		animal-babies-and-homes
Male swan	Cob		animal-babies-and-homes
Female swan	Pen		animal-babies-and-homes
Male turkey	Tom		animal-babies-and-homes
Where does a bird live?	In a nest		animal-babies-and-homes
Where does a bee live?	In a hive		animal-babies-and-homes
Where does an ant live?	In an anthill or colony		animal-babies-and-homes
Where does a spider live?	On a web		animal-babies-and-homes
Where does a bear sleep in winter?	In a den		animal-babies-and-homes
Where does a beaver live?	In a lodge		animal-babies-and-homes
Where does a fox live?	In a den or burrow		animal-babies-and-homes
Where does a rabbit live?	In a burrow or warren		animal-babies-and-homes
Where does a horse live?	In a stable		animal-babies-and-homes
Where does a cow live?	In a barn or pasture		animal-babies-and-homes
Where does a pig live?	In a pen or sty		animal-babies-and-homes
Where does a chicken live?	In a coop		animal-babies-and-homes
Where does a dog live?	In a house or kennel		animal-babies-and-homes
Where does a fish live?	In water		animal-babies-and-homes
Where does an eagle live?	In an eyrie, a high nest		animal-babies-and-homes
Where does a squirrel live?	In a tree nest called a drey		animal-babies-and-homes
Where does a mole live?	Underground in tunnels		animal-babies-and-homes
Where does a wasp live?	In a paper nest		animal-babies-and-homes
Where does a polar bear live?	In the Arctic		animal-babies-and-homes
Where does a penguin live?	Mostly in the Southern Hemisphere, many in Antarctica		animal-babies-and-homes
Where does a camel live?	In deserts		animal-babies-and-homes
Where does a monkey live?	In forests and jungles		animal-babies-and-homes
Where does an octopus live?	In the sea, often in a den among rocks		animal-babies-and-homes
Where does a whale live?	In the ocean		animal-babies-and-homes
Bald eagle	The national bird of the United States; has a white head as an adult		animal-birds
Peregrine falcon	The fastest bird in a dive		animal-birds
Ostrich	The largest bird; cannot fly but runs fast		animal-birds
Emperor penguin	The largest penguin; lives in Antarctica		animal-birds
Bee hummingbird	The smallest bird, from Cuba		animal-birds
Hummingbird	Can hover and fly backward; drinks nectar		animal-birds
Albatross	A seabird with one of the longest wingspans		animal-birds
Owl	A night hunter with silent flight and big eyes		animal-birds
Barn owl	A pale owl with a heart-shaped face		animal-birds
Great horned owl	An owl with tufts that look like horns		animal-birds
Snowy owl	A white Arctic owl		animal-birds
Robin	A songbird with an orange-red breast		animal-birds
Blue jay	A loud blue crested bird		animal-birds
Cardinal	A bright red songbird; males are red		animal-birds
Crow	A very smart black bird		animal-birds
Raven	A large black bird, bigger than a crow		animal-birds
Magpie	A black and white bird of the crow family		animal-birds
Sparrow	A small brown songbird		animal-birds
Finch	A small seed-eating songbird		animal-birds
Chickadee	A tiny gray-and-black bird with a call that says its name		animal-birds
Woodpecker	Pecks at trees for insects		animal-birds
Toucan	A tropical bird with a huge colorful beak		animal-birds
Parrot	A colorful bird that can copy sounds		animal-birds
Macaw	A large colorful parrot		animal-birds
Flamingo	A pink wading bird that often stands on one leg		animal-birds
Heron	A tall wading bird that hunts fish		animal-birds
Crane	A tall bird known for dancing displays		animal-birds
Stork	A long-legged wading bird		animal-birds
Pelican	A seabird with a large throat pouch		animal-birds
Seagull	A common bird at the shore		animal-birds
Puffin	A seabird with a colorful beak, called the clown of the sea		animal-birds
Cormorant	A diving bird that dries its wings in the sun		animal-birds
Swan	A graceful long-necked water bird		animal-birds
Goose	A large water bird that flies in V formation		animal-birds
Mallard	The most common wild duck; males have green heads		animal-birds
Wood duck	A colorful duck that nests in trees		animal-birds
Loon	A diving water bird with a haunting call		animal-birds
Kiwi	A flightless bird from New Zealand		animal-birds
Emu	A large flightless bird from Australia		animal-birds
Cassowary	A large flightless bird with a bony crest, from Australia and New Guinea		animal-birds
Rhea	A large flightless bird from South America		animal-birds
Peacock	A male peafowl with a fan of colorful tail feathers		animal-birds
Turkey	A large ground bird; wild turkeys live in North America		animal-birds
Chicken	A farm bird kept for eggs and meat		animal-birds
Pigeon	A city bird that can find its way home		animal-birds
Dove	A gentle bird related to pigeons		animal-birds
Mockingbird	A songbird that mimics other sounds		animal-birds
Meadowlark	A grassland bird with a yellow chest		animal-birds
Kingfisher	A bird that dives to catch fish		animal-birds
Hawk	A hunting bird with sharp talons		animal-birds
Red-tailed hawk	A common hawk with a reddish tail		animal-birds
Osprey	A hawk-like bird that dives for fish		animal-birds
Vulture	A scavenger that eats dead animals		animal-birds
California condor	A giant vulture that was brought back from near extinction		animal-birds
Secretary bird	An African bird that stomps on snakes		animal-birds
Roadrunner	A fast-running bird of the American Southwest		animal-birds
Cuckoo	A bird that lays eggs in other birds' nests		animal-birds
Swallow	A fast flyer that catches insects in the air		animal-birds
Swift	A bird that eats and sleeps in flight		animal-birds
Arctic tern	Migrates from Arctic to Antarctic each year		animal-birds
Bar-tailed godwit	A bird that flies nonstop across the Pacific		animal-birds
Penguin	A flightless bird that swims using flippers		animal-birds
Dodo	An extinct flightless bird from Mauritius		animal-birds
Passenger pigeon	A once-numerous North American bird that went extinct in 1914		animal-birds
Wren	A small, brown, perky songbird		animal-birds
Oriole	A bright orange and black songbird		animal-birds
Bluebird	A small blue songbird		animal-birds
Goldfinch	A small yellow songbird		animal-birds
Starling	A glossy bird that flies in huge flocks		animal-birds
Bird feathers	Light, strong coverings that help flight and keep birds warm		animal-birds
Beak	A bird's mouth; shape depends on what it eats		animal-birds
Talons	Sharp claws of birds of prey		animal-birds
Nest	A home where birds lay eggs		animal-birds
Incubate	To sit on eggs to keep them warm		animal-birds
Fledgling	A young bird learning to fly		animal-birds
Molting	Shedding old feathers and growing new ones		animal-birds
Preening	A bird cleaning and arranging its feathers		animal-birds
Migration	Birds traveling long distances with the seasons		animal-birds
Bird of prey	A bird that hunts other animals, like eagles		animal-birds
Waterfowl	Ducks, geese and swans		animal-birds
Songbird	A bird that sings, such as a robin		animal-birds
Flightless bird	A bird that can't fly, such as an ostrich or kiwi		animal-birds
Ornithology	The study of birds		animal-birds
Birdsong	Sounds birds make to claim territory or attract mates		animal-birds
Mammals	Warm-blooded animals with hair or fur that feed their babies milk		animal-classes-facts
Birds	Warm-blooded animals with feathers, wings and beaks that lay eggs		animal-classes-facts
Reptiles	Cold-blooded animals with dry scaly skin		animal-classes-facts
Amphibians	Animals that start life in water and often live on land as adults		animal-classes-facts
Fish	Cold-blooded animals with gills and fins that live in water		animal-classes-facts
Insects	Animals with six legs and three body parts		animal-classes-facts
Arachnids	Animals with eight legs, like spiders		animal-classes-facts
Crustaceans	Animals with a hard shell and many legs, like crabs		animal-classes-facts
Mollusks	Soft-bodied animals often with shells, like snails		animal-classes-facts
Vertebrate	An animal with a backbone		animal-classes-facts
Invertebrate	An animal without a backbone		animal-classes-facts
Warm-blooded	Keeps a steady body temperature		animal-classes-facts
Cold-blooded	Body temperature changes with the surroundings		animal-classes-facts
Is a bat a bird or a mammal?	A mammal		animal-classes-facts
Is a whale a fish or a mammal?	A mammal		animal-classes-facts
Is a dolphin a fish or a mammal?	A mammal		animal-classes-facts
Is a penguin a bird?	Yes, a flightless bird		animal-classes-facts
Is a frog a reptile or an amphibian?	An amphibian		animal-classes-facts
Is a snake a reptile or an amphibian?	A reptile		animal-classes-facts
Is a spider an insect?	No; it's an arachnid with eight legs		animal-classes-facts
Is a shark a mammal or a fish?	A fish		animal-classes-facts
Is a platypus a mammal that lays eggs?	Yes		animal-classes-facts
Which mammals lay eggs?	Monotremes: the platypus and echidnas		animal-classes-facts
Which mammals have pouches?	Marsupials, like kangaroos and koalas		animal-classes-facts
Largest animal on Earth	The blue whale		animal-classes-facts
Largest land animal	The African elephant		animal-classes-facts
Tallest animal	The giraffe		animal-classes-facts
Fastest land animal	The cheetah		animal-classes-facts
Fastest bird in a dive	The peregrine falcon		animal-classes-facts
Largest bird alive	The ostrich		animal-classes-facts
Smallest bird	The bee hummingbird		animal-classes-facts
Largest reptile	The saltwater crocodile		animal-classes-facts
Largest fish	The whale shark		animal-classes-facts
Largest living cat	The tiger		animal-classes-facts
Largest land carnivore	The polar bear		animal-classes-facts
Slowest mammal	The sloth		animal-classes-facts
Longest living land animal	The Galapagos giant tortoise, over 100 years		animal-classes-facts
Largest rodent	The capybara		animal-classes-facts
Largest primate	The gorilla		animal-classes-facts
Only mammal that can truly fly	The bat		animal-classes-facts
Which animal has the largest eyes?	The giant squid		animal-classes-facts
How many legs does an insect have?	Six		animal-classes-facts
How many legs does a spider have?	Eight		animal-classes-facts
How many legs does a crab have?	Ten		animal-classes-facts
How many arms does an octopus have?	Eight		animal-classes-facts
Insect body parts	Head, thorax and abdomen		animal-classes-facts
Metamorphosis	A big change in body form as an animal grows		animal-classes-facts
Complete metamorphosis	Egg, larva, pupa, adult		animal-classes-facts
Incomplete metamorphosis	Egg, nymph, adult		animal-classes-facts
Butterfly life cycle	Egg, caterpillar, chrysalis, butterfly		animal-classes-facts
Frog life cycle	Egg, tadpole, froglet, adult frog		animal-classes-facts
Exoskeleton	A hard outer covering that supports and protects the body		animal-classes-facts
Molting	Shedding an old outer layer		animal-classes-facts
Herd animals	Cattle, zebras and elephants live in herds		animal-classes-facts
Pack animals	Wolves and wild dogs hunt in packs		animal-classes-facts
Predator	An animal that hunts others		animal-classes-facts
Prey	An animal that is hunted		animal-classes-facts
Scavenger	Eats dead animals it did not kill, like vultures		animal-classes-facts
Vultures help by	Cleaning up dead animals		animal-classes-facts
Marine mammal	A mammal that lives in the sea, like seals and whales		animal-classes-facts
Endangered animal	A species in danger of dying out		animal-classes-facts
Extinct animal	A species that has died out		animal-classes-facts
Dodo	A flightless bird from Mauritius that went extinct in the 1600s		animal-classes-facts
Lions	A pride		animal-groups-collective
Wolves	A pack		animal-groups-collective
Fish	A school (or shoal)		animal-groups-collective
Whales	A pod		animal-groups-collective
Dolphins	A pod		animal-groups-collective
Geese on the ground	A gaggle		animal-groups-collective
Geese in the air	A skein		animal-groups-collective
Crows	A murder		animal-groups-collective
Owls	A parliament		animal-groups-collective
Ducks on water	A paddling		animal-groups-collective
Bees	A swarm or colony		animal-groups-collective
Ants	A colony		animal-groups-collective
Cattle	A herd		animal-groups-collective
Sheep	A flock		animal-groups-collective
Birds	A flock		animal-groups-collective
Elephants	A herd		animal-groups-collective
Giraffes	A tower		animal-groups-collective
Zebras	A dazzle		animal-groups-collective
Hippos	A bloat		animal-groups-collective
Rhinos	A crash		animal-groups-collective
Apes	A shrewdness		animal-groups-collective
Monkeys	A troop		animal-groups-collective
Gorillas	A band or troop		animal-groups-collective
Kangaroos	A mob		animal-groups-collective
Bears	A sleuth or sloth		animal-groups-collective
Foxes	A skulk		animal-groups-collective
Hyenas	A cackle		animal-groups-collective
Cats	A clowder		animal-groups-collective
Kittens	A kindle or litter		animal-groups-collective
Puppies	A litter		animal-groups-collective
Horses	A herd		animal-groups-collective
Pigs	A drove or herd		animal-groups-collective
Goats	A herd or tribe		animal-groups-collective
Deer	A herd		animal-groups-collective
Buffalo	A herd		animal-groups-collective
Camels	A caravan		animal-groups-collective
Penguins on land	A colony or waddle		animal-groups-collective
Flamingos	A flamboyance		animal-groups-collective
Peacocks	An ostentation		animal-groups-collective
Parrots	A pandemonium		animal-groups-collective
Ravens	An unkindness		animal-groups-collective
Eagles	A convocation		animal-groups-collective
Hawks	A kettle (when circling)		animal-groups-collective
Starlings	A murmuration		animal-groups-collective
Swans	A bevy or wedge		animal-groups-collective
Turkeys	A rafter or flock		animal-groups-collective
Chickens	A flock or brood		animal-groups-collective
Frogs	An army		animal-groups-collective
Toads	A knot		animal-groups-collective
Snakes	A nest or knot		animal-groups-collective
Turtles	A bale		animal-groups-collective
Crocodiles	A float or bask		animal-groups-collective
Sharks	A shiver		animal-groups-collective
Jellyfish	A smack or bloom		animal-groups-collective
Seals	A colony or pod		animal-groups-collective
Otters on water	A raft		animal-groups-collective
Beavers	A colony		animal-groups-collective
Squirrels	A scurry		animal-groups-collective
Rabbits	A colony or warren		animal-groups-collective
Mice	A mischief		animal-groups-collective
Rats	A mischief		animal-groups-collective
Porcupines	A prickle		animal-groups-collective
Moles	A labour		animal-groups-collective
Butterflies	A kaleidoscope		animal-groups-collective
Caterpillars	An army		animal-groups-collective
Locusts	A plague or swarm		animal-groups-collective
Fireflies	A glow		animal-groups-collective
Jays	A party		animal-groups-collective
Finches	A charm		animal-groups-collective
Larks	An exaltation		animal-groups-collective
Cranes	A sedge		animal-groups-collective
Lemurs	A conspiracy		animal-groups-collective
Leopards	A leap		animal-groups-collective
Tigers	A streak or ambush		animal-groups-collective
Cheetahs	A coalition		animal-groups-collective
Crabs	A cast		animal-groups-collective
Oysters	A bed		animal-groups-collective
Insect	An animal with six legs and three body parts		animal-insects-bugs
Arthropod	An animal with jointed legs and an exoskeleton		animal-insects-bugs
Ant	A social insect that lives in colonies with a queen		animal-insects-bugs
Honeybee	An insect that makes honey and pollinates flowers		animal-insects-bugs
Bumblebee	A fuzzy, large bee		animal-insects-bugs
Wasp	A stinging insect, many build paper nests		animal-insects-bugs
Hornet	A large wasp		animal-insects-bugs
Butterfly	An insect with colorful wings that drinks nectar		animal-insects-bugs
Moth	A mostly nocturnal relative of butterflies		animal-insects-bugs
Monarch butterfly	An orange and black butterfly that migrates		animal-insects-bugs
Caterpillar	The larva of a butterfly or moth		animal-insects-bugs
Chrysalis	The hard case a butterfly pupa lives in		animal-insects-bugs
Cocoon	A silk case made by many moth larvae		animal-insects-bugs
Ladybug	A small red beetle with spots that eats aphids		animal-insects-bugs
Beetle	An insect with hard front wings; the largest group of animals		animal-insects-bugs
Firefly (lightning bug)	A beetle that glows to find mates		animal-insects-bugs
Dragonfly	A fast insect with two pairs of wings that eats mosquitoes		animal-insects-bugs
Damselfly	A slimmer relative of the dragonfly		animal-insects-bugs
Grasshopper	An insect with strong back legs for jumping		animal-insects-bugs
Cricket	An insect that chirps by rubbing its wings together		animal-insects-bugs
Katydid	A green insect like a grasshopper that sings at night		animal-insects-bugs
Praying mantis	An insect that catches prey with spiny front legs		animal-insects-bugs
Stick insect	An insect that looks like a twig		animal-insects-bugs
Cicada	An insect that spends years underground and then sings loudly		animal-insects-bugs
Aphid	A tiny plant-sucking insect		animal-insects-bugs
Mosquito	A small flying insect; females drink blood		animal-insects-bugs
Housefly	A common fly that tastes with its feet		animal-insects-bugs
Flea	A tiny jumping insect that lives on animals		animal-insects-bugs
Termite	An insect that eats wood and builds big mounds		animal-insects-bugs
Cockroach	A hardy insect found all over the world		animal-insects-bugs
Earwig	An insect with pincers at the tail		animal-insects-bugs
Mayfly	An insect whose adult stage lasts only a day or so		animal-insects-bugs
Water strider	A bug that walks on water		animal-insects-bugs
Dung beetle	A beetle that rolls dung into balls		animal-insects-bugs
Rhinoceros beetle	A strong beetle with a horn		animal-insects-bugs
Goliath beetle	One of the heaviest insects		animal-insects-bugs
Silkworm	A caterpillar that spins silk, used to make cloth		animal-insects-bugs
Spider	An arachnid with eight legs that makes silk		animal-insects-bugs
Tarantula	A large hairy spider		animal-insects-bugs
Black widow	A venomous spider with a red hourglass mark		animal-insects-bugs
Orb weaver	A spider that makes round webs		animal-insects-bugs
Jumping spider	A small spider with great eyesight		animal-insects-bugs
Scorpion	An arachnid with pincers and a stinging tail		animal-insects-bugs
Tick	A small blood-sucking arachnid		animal-insects-bugs
Mite	A tiny arachnid		animal-insects-bugs
Millipede	A many-legged arthropod that eats decaying matter		animal-insects-bugs
Centipede	An arthropod with one pair of legs per body segment		animal-insects-bugs
Pill bug (roly-poly)	A crustacean that curls into a ball		animal-insects-bugs
Snail	A mollusk with a spiral shell, not an insect		animal-insects-bugs
Slug	A snail without a shell, not an insect		animal-insects-bugs
Earthworm	A segmented worm that loosens soil		animal-insects-bugs
Antennae	Feelers on an insect's head for smelling and touching		animal-insects-bugs
Compound eye	An eye made of many tiny lenses		animal-insects-bugs
Thorax	The middle body part where wings and legs attach		animal-insects-bugs
Abdomen	The rear body part of an insect		animal-insects-bugs
Exoskeleton	A hard outer skeleton		animal-insects-bugs
Metamorphosis	Big change in body form during growth		animal-insects-bugs
Complete metamorphosis	Egg, larva, pupa, adult		animal-insects-bugs
Incomplete metamorphosis	Egg, nymph, adult		animal-insects-bugs
Larva	A young insect that looks different from the adult		animal-insects-bugs
Pupa	A resting stage between larva and adult		animal-insects-bugs
Nymph	A young insect that looks like a small adult		animal-insects-bugs
Pollinator	An animal that carries pollen between flowers		animal-insects-bugs
Colony	A group of social insects living together		animal-insects-bugs
Queen bee	The egg-laying bee in a hive		animal-insects-bugs
Worker bee	A female bee that collects food and builds the hive		animal-insects-bugs
Drone	A male bee		animal-insects-bugs
Hive	A bee home		animal-insects-bugs
Honeycomb	Wax cells where bees store honey and raise young		animal-insects-bugs
Waggle dance	How honeybees tell others where flowers are		animal-insects-bugs
Anthill	A mound of earth built by ants		animal-insects-bugs
Camouflage in insects	Walking sticks and leaf insects blend in		animal-insects-bugs
Entomologist	A scientist who studies insects		animal-insects-bugs
Insect with the most species	Beetles		animal-insects-bugs
Do spiders count as insects?	No; they have eight legs and two body parts		animal-insects-bugs
Silk	Strong thread made by spiders and silkworms		animal-insects-bugs
Web	A trap made of spider silk		animal-insects-bugs
Insect wings	Most adult insects have four wings; flies have two		animal-insects-bugs
Pheromone	A chemical signal used by insects		animal-insects-bugs
Beneficial insects	Insects that help people, like bees and ladybugs		animal-insects-bugs
Pest	An insect that harms crops or spreads disease		animal-insects-bugs
Reptile	A cold-blooded animal with dry scaly skin that usually lays eggs		animal-reptiles-amphibians
Amphibian	A cold-blooded animal with moist skin that starts life in water		animal-reptiles-amphibians
Snake	A legless reptile that swallows prey whole		animal-reptiles-amphibians
Lizard	A reptile with legs and a long tail, usually		animal-reptiles-amphibians
Turtle	A reptile with a shell that can often live in water		animal-reptiles-amphibians
Tortoise	A land turtle with stumpy legs and a domed shell		animal-reptiles-amphibians
Crocodile	A large reptile with a pointed snout		animal-reptiles-amphibians
Alligator	A large reptile with a rounded snout		animal-reptiles-amphibians
Gecko	A lizard that can climb walls with sticky toes		animal-reptiles-amphibians
Chameleon	A lizard that changes color and has a long sticky tongue		animal-reptiles-amphibians
Iguana	A large plant-eating lizard		animal-reptiles-amphibians
Komodo dragon	The largest living lizard		animal-reptiles-amphibians
Gila monster	A venomous lizard of the American Southwest		animal-reptiles-amphibians
Horned lizard	A spiky lizard that can squirt blood from its eyes to scare predators		animal-reptiles-amphibians
Anole	A small lizard that can puff out a throat fan		animal-reptiles-amphibians
Skink	A shiny smooth-scaled lizard		animal-reptiles-amphibians
Python	A large snake that squeezes prey		animal-reptiles-amphibians
Boa constrictor	A snake that squeezes its prey		animal-reptiles-amphibians
Anaconda	One of the heaviest snakes, living in South America		animal-reptiles-amphibians
King cobra	The longest venomous snake		animal-reptiles-amphibians
Rattlesnake	A venomous snake with a rattle on its tail		animal-reptiles-amphibians
Garter snake	A harmless, common snake with stripes		animal-reptiles-amphibians
Coral snake	A venomous snake with red, yellow and black bands		animal-reptiles-amphibians
Sea turtle	A turtle adapted to the ocean		animal-reptiles-amphibians
Snapping turtle	A freshwater turtle with a strong bite		animal-reptiles-amphibians
Leatherback turtle	The largest sea turtle		animal-reptiles-amphibians
Galapagos tortoise	The largest living tortoise		animal-reptiles-amphibians
Tuatara	A lizard-like reptile from New Zealand		animal-reptiles-amphibians
Frog	An amphibian with smooth skin and long legs for jumping		animal-reptiles-amphibians
Toad	An amphibian with dry, bumpy skin		animal-reptiles-amphibians
Tree frog	A small frog with sticky toe pads		animal-reptiles-amphibians
Poison dart frog	A tiny brightly colored frog with toxic skin		animal-reptiles-amphibians
Bullfrog	A large frog with a deep call		animal-reptiles-amphibians
Salamander	An amphibian with a long tail and four legs		animal-reptiles-amphibians
Newt	A kind of salamander that spends time in water		animal-reptiles-amphibians
Axolotl	A salamander that keeps its gills and can regrow limbs		animal-reptiles-amphibians
Hellbender	A giant salamander of North American streams		animal-reptiles-amphibians
Caecilian	A legless amphibian that looks like a worm		animal-reptiles-amphibians
Tadpole	A baby frog or toad that lives in water		animal-reptiles-amphibians
Metamorphosis in frogs	Tadpole grows legs, loses its tail and gills, and breathes air		animal-reptiles-amphibians
Frog life cycle	Egg, tadpole, froglet, adult		animal-reptiles-amphibians
Reptile eggs	Leathery shells laid on land		animal-reptiles-amphibians
Amphibian eggs	Jelly-like eggs laid in water		animal-reptiles-amphibians
Cold-blooded	Body temperature depends on the surroundings		animal-reptiles-amphibians
Basking	Sitting in the sun to warm up		animal-reptiles-amphibians
Shedding skin	Snakes and lizards shed their outer skin as they grow		animal-reptiles-amphibians
Scutes	The bony plates on a turtle's shell		animal-reptiles-amphibians
Carapace	The top part of a turtle's shell		animal-reptiles-amphibians
Plastron	The bottom part of a turtle's shell		animal-reptiles-amphibians
Forked tongue	Helps snakes smell their surroundings		animal-reptiles-amphibians
Jacobson's organ	A smell organ on the roof of a snake's mouth		animal-reptiles-amphibians
Venom	Poison injected by a bite or sting		animal-reptiles-amphibians
Constrictor	A snake that squeezes prey		animal-reptiles-amphibians
Brumation	A reptile's winter slowdown, like hibernation		animal-reptiles-amphibians
Camouflage in reptiles	Chameleons and geckos can blend into their surroundings		animal-reptiles-amphibians
Tail dropping	Some lizards drop their tails to escape and regrow them		animal-reptiles-amphibians
Frog call	Males call to attract mates		animal-reptiles-amphibians
Do frogs drink with their mouths?	They absorb water through their skin		animal-reptiles-amphibians
Herpetologist	A scientist who studies reptiles and amphibians		animal-reptiles-amphibians
Dinosaur relatives alive today	Crocodiles, as well as birds, are dinosaur relatives		animal-reptiles-amphibians
Largest living reptile	Saltwater crocodile		animal-reptiles-amphibians
Smallest chameleons	Brookesia micra, only about an inch long		animal-reptiles-amphibians
Why do amphibians need clean water?	Their thin skin absorbs substances easily		animal-reptiles-amphibians
Why are frogs a warning sign for the environment?	They react quickly to pollution and habitat change		animal-reptiles-amphibians
Circulatory system	Moves blood, oxygen and nutrients around the body		bio-body-systems
Respiratory system	Brings in oxygen and removes carbon dioxide		bio-body-systems
Digestive system	Breaks down food and absorbs nutrients		bio-body-systems
Nervous system	Sends signals between the brain and body		bio-body-systems
Skeletal system	Supports the body, protects organs and makes blood cells		bio-body-systems
Muscular system	Moves the body and keeps the heart beating		bio-body-systems
Excretory (urinary) system	Removes liquid waste and balances water		bio-body-systems
Endocrine system	Uses hormones to control growth and body activities		bio-body-systems
Immune system	Defends the body against germs		bio-body-systems
Lymphatic system	Drains fluid and helps fight infection		bio-body-systems
Integumentary system	Skin, hair and nails; protects the body		bio-body-systems
Reproductive system	Makes new life		bio-body-systems
Main organs of the circulatory system	Heart, blood vessels and blood		bio-body-systems
Main organs of the respiratory system	Nose, trachea, bronchi and lungs		bio-body-systems
Main organs of the digestive system	Mouth, esophagus, stomach, intestines, liver, pancreas		bio-body-systems
Main organs of the nervous system	Brain, spinal cord and nerves		bio-body-systems
Main organs of the excretory system	Kidneys, ureters, bladder and urethra		bio-body-systems
Heart	Muscle that pumps blood		bio-body-systems
Lungs	Organs where oxygen enters the blood		bio-body-systems
Brain	Control center of the body		bio-body-systems
Stomach	Churns food with acid and enzymes		bio-body-systems
Small intestine	Absorbs most nutrients from food		bio-body-systems
Large intestine	Absorbs water and forms waste		bio-body-systems
Liver	Cleans blood and makes bile		bio-body-systems
Pancreas	Makes insulin and digestive enzymes		bio-body-systems
Kidneys	Filter blood and make urine		bio-body-systems
Skin	The body's largest organ		bio-body-systems
Esophagus	Tube that carries food from mouth to stomach		bio-body-systems
Trachea	Windpipe that carries air to the lungs		bio-body-systems
Diaphragm	Muscle below the lungs that helps you breathe		bio-body-systems
Alveoli	Tiny air sacs in the lungs where gases are exchanged		bio-body-systems
Artery	Blood vessel that carries blood away from the heart		bio-body-systems
Vein	Blood vessel that carries blood to the heart		bio-body-systems
Capillary	Tiny blood vessel where materials pass into and out of the blood		bio-body-systems
Red blood cells	Carry oxygen		bio-body-systems
White blood cells	Fight germs		bio-body-systems
Platelets	Help blood clot		bio-body-systems
Plasma	The liquid part of blood		bio-body-systems
Hemoglobin	Protein in red blood cells that carries oxygen		bio-body-systems
Neuron	Nerve cell		bio-body-systems
Spinal cord	Bundle of nerves in the backbone that links brain and body		bio-body-systems
Reflex	A fast automatic response		bio-body-systems
Hormone	A chemical messenger made by glands		bio-body-systems
Thyroid	Gland in the neck that controls metabolism		bio-body-systems
Pituitary gland	Small master gland at the base of the brain		bio-body-systems
Adrenal glands	Make adrenaline for the fight-or-flight response		bio-body-systems
Saliva	Starts breaking down food in the mouth		bio-body-systems
Bile	Fluid from the liver that helps digest fats		bio-body-systems
Peristalsis	Wave-like muscle squeezes that push food along		bio-body-systems
Antibody	A protein that fights a particular germ		bio-body-systems
Vaccine	Trains the immune system to recognize a germ		bio-body-systems
Epidermis	The outer layer of skin		bio-body-systems
Dermis	The thicker layer of skin below the epidermis		bio-body-systems
Melanin	Pigment that gives skin color and protects from the Sun		bio-body-systems
Pulse	The beat felt as the heart pushes blood through arteries		bio-body-systems
Blood pressure	The force of blood against vessel walls		bio-body-systems
Homeostasis	The body keeping conditions steady inside		bio-body-systems
Metabolism	All the chemical reactions that keep an organism alive		bio-body-systems
Which system includes the stomach?	Digestive		bio-body-systems
Which system includes the bones?	Skeletal		bio-body-systems
Which system includes the heart?	Circulatory		bio-body-systems
Which system includes the lungs?	Respiratory		bio-body-systems
Which system includes the brain?	Nervous		bio-body-systems
Cranium	The skull bones that protect the brain		bio-bones
Mandible	The jawbone; the only movable bone of the skull		bio-bones
Maxilla	The upper jaw		bio-bones
Clavicle	The collarbone		bio-bones
Scapula	The shoulder blade		bio-bones
Sternum	The breastbone in the middle of the chest		bio-bones
Ribs	Curved bones that protect the heart and lungs		bio-bones
Vertebrae	The bones of the backbone		bio-bones
Spine (vertebral column)	Supports the body and protects the spinal cord		bio-bones
Humerus	The upper arm bone		bio-bones
Radius	Forearm bone on the thumb side		bio-bones
Ulna	Forearm bone on the pinky side		bio-bones
Carpals	The wrist bones		bio-bones
Metacarpals	The bones of the palm of the hand		bio-bones
Phalanges	The bones of the fingers and toes		bio-bones
Pelvis	The hip bones that support the upper body		bio-bones
Femur	The thigh bone; the longest and strongest bone		bio-bones
Patella	The kneecap		bio-bones
Tibia	The shinbone, the larger lower leg bone		bio-bones
Fibula	The thinner lower leg bone		bio-bones
Tarsals	The ankle bones		bio-bones
Metatarsals	The bones of the middle of the foot		bio-bones
Calcaneus	The heel bone		bio-bones
Coccyx	The tailbone		bio-bones
Sacrum	Triangle-shaped bone at the base of the spine		bio-bones
Stapes	Smallest bone in the body, in the ear		bio-bones
Malleus	The hammer bone in the ear		bio-bones
Incus	The anvil bone in the ear		bio-bones
How many bones does an adult have?	206		bio-bones
How many bones does a baby have, about?	Around 300, some of which fuse		bio-bones
Cervical vertebrae	The 7 neck bones		bio-bones
Thoracic vertebrae	The 12 vertebrae in the upper and middle back		bio-bones
Lumbar vertebrae	The 5 vertebrae of the lower back		bio-bones
How many pairs of ribs do people have?	12 pairs		bio-bones
Joint	Where two bones meet		bio-bones
Ligament	Tough tissue that connects bone to bone		bio-bones
Tendon	Tough tissue that connects muscle to bone		bio-bones
Cartilage	Flexible tissue that cushions joints and shapes ears and nose		bio-bones
Marrow	Soft tissue inside bones that makes blood cells		bio-bones
Ball-and-socket joint	A joint that moves in all directions, like the shoulder and hip		bio-bones
Hinge joint	A joint that moves back and forth, like the knee and elbow		bio-bones
Pivot joint	A joint that rotates, like the neck		bio-bones
Gliding joint	A joint where bones slide past each other, as in the wrist		bio-bones
Fixed (immovable) joint	A joint that does not move, as in the skull		bio-bones
Calcium	The mineral that makes bones hard		bio-bones
Osteoporosis	A condition in which bones become weak and thin		bio-bones
Fracture	A break in a bone		bio-bones
Hyoid	A small U-shaped bone in the neck that supports the tongue		bio-bones
Zygomatic bone	The cheekbone		bio-bones
Occipital bone	The bone at the back and base of the skull		bio-bones
Frontal bone	The forehead bone		bio-bones
Sutures	The joints between skull bones		bio-bones
Axial skeleton	Skull, spine and rib cage		bio-bones
Appendicular skeleton	The limbs and the bones that attach them		bio-bones
Periosteum	The tough covering on the outside of a bone		bio-bones
Compact bone	The hard, dense outer layer of bone		bio-bones
Spongy bone	Lighter bone with small holes inside		bio-bones
Cell	The basic unit of all living things		bio-cell-parts
Nucleus	Holds the DNA and controls the cell's activities		bio-cell-parts
Nucleolus	Inside the nucleus; makes parts of ribosomes		bio-cell-parts
Nuclear envelope	Double membrane that surrounds the nucleus		bio-cell-parts
Cell membrane	Thin outer layer that controls what enters and leaves		bio-cell-parts
Cell wall	Rigid outer layer that supports plant, fungus and bacteria cells		bio-cell-parts
Cytoplasm	Jelly-like fluid that fills the cell		bio-cell-parts
Cytosol	The liquid part of the cytoplasm		bio-cell-parts
Mitochondrion	Releases energy from food (The powerhouse of the cell)		bio-cell-parts
Chloroplast	Where plants make food by photosynthesis		bio-cell-parts
Ribosome	Builds proteins		bio-cell-parts
Rough endoplasmic reticulum	Folded membranes covered in ribosomes; makes proteins		bio-cell-parts
Smooth endoplasmic reticulum	Makes lipids and helps remove toxins		bio-cell-parts
Golgi apparatus	Packages and ships proteins and lipids (Like the post office)		bio-cell-parts
Vacuole	Storage sac for water, food and waste		bio-cell-parts
Central vacuole	Large water-filled sac in plant cells that gives support		bio-cell-parts
Lysosome	Contains enzymes that break down waste and old parts		bio-cell-parts
Vesicle	Small sac that moves materials inside the cell		bio-cell-parts
Cytoskeleton	Network of fibers that gives shape and helps movement		bio-cell-parts
Centriole	Helps organize cell division in animal cells		bio-cell-parts
Flagellum	Whip-like tail that helps a cell swim		bio-cell-parts
Cilia	Short hair-like structures that move fluid or the cell		bio-cell-parts
Pseudopod	A temporary arm-like extension, as in amoeba		bio-cell-parts
Plasmid	A small ring of DNA in bacteria		bio-cell-parts
Chromosome	A coiled package of DNA		bio-cell-parts
Chromatin	DNA and proteins in the nucleus when the cell is not dividing		bio-cell-parts
Peroxisome	Breaks down fats and harmful substances like hydrogen peroxide		bio-cell-parts
Thylakoid	Disk-like membranes in chloroplasts where light is captured		bio-cell-parts
Stroma	Fluid inside chloroplasts where sugar is built		bio-cell-parts
Cristae	Folds in the inner membrane of the mitochondrion		bio-cell-parts
Prokaryote	A cell without a nucleus, like bacteria		bio-cell-parts
Eukaryote	A cell with a nucleus and organelles		bio-cell-parts
Do animal cells have cell walls?	No		bio-cell-parts
Do plant cells have chloroplasts?	Yes		bio-cell-parts
Do animal cells have chloroplasts?	No		bio-cell-parts
Organelle	A tiny structure inside a cell with a specific job		bio-cell-parts
Tissue	A group of similar cells working together		bio-cell-parts
Organ	A group of tissues working together		bio-cell-parts
Organ system	A group of organs working together		bio-cell-parts
Organism	A whole living thing		bio-cell-parts
Unicellular	Made of just one cell		bio-cell-parts
Multicellular	Made of many cells		bio-cell-parts
Cell theory: first idea	All living things are made of one or more cells		bio-cell-parts
Cell theory: second idea	The cell is the basic unit of life		bio-cell-parts
Cell theory: third idea	All cells come from other cells		bio-cell-parts
Who first named cells in 1665?	Robert Hooke, looking at cork		bio-cell-parts
Who first saw living microbes with a microscope?	Antonie van Leeuwenhoek		bio-cell-parts
Selectively permeable	Lets some things through the membrane but not others		bio-cell-parts
Phospholipid bilayer	The double layer of fat molecules that makes up a membrane		bio-cell-parts
Diffusion	Particles moving from crowded to less crowded areas		bio-cell-parts
Osmosis	Diffusion of water across a membrane		bio-cell-parts
Active transport	Moving materials across a membrane using energy		bio-cell-parts
Passive transport	Moving materials across a membrane without energy		bio-cell-parts
Endocytosis	The cell takes material in by wrapping the membrane around it		bio-cell-parts
Exocytosis	The cell sends material out in vesicles		bio-cell-parts
Mitosis	Cell division that makes two identical cells		bio-cell-parts
Cytokinesis	The splitting of the cytoplasm at the end of cell division		bio-cell-parts
Meiosis	Cell division that makes sex cells with half the chromosomes		bio-cell-parts
Cell cycle	The life of a cell from one division to the next		bio-cell-parts
Stem cell	A cell that can become many different types of cells		bio-cell-parts
Red blood cell	Carries oxygen in blood and has no nucleus		bio-cell-parts
White blood cell	Helps the body fight germs		bio-cell-parts
Neuron	A nerve cell that carries signals		bio-cell-parts
Guard cells	Pairs of plant cells that open and close stomata		bio-cell-parts
Taxonomy	The science of naming and classifying living things		bio-classification
Who created the system of naming species with two names?	Carl Linnaeus		bio-classification
Binomial nomenclature	Naming each species with a two-part Latin name		bio-classification
Genus	The first part of a scientific name, capitalized		bio-classification
Species	The second part of a scientific name, lowercase; a group that can breed together		bio-classification
Scientific name of humans	Homo sapiens		bio-classification
Scientific name of the domestic dog	Canis familiaris		bio-classification
Scientific name of the house cat	Felis catus		bio-classification
Taxonomic ranks from biggest to smallest	Domain, kingdom, phylum, class, order, family, genus, species		bio-classification
Memory trick for ranks	Dear King Philip Came Over For Good Soup		bio-classification
How many domains of life are there?	Three: Bacteria, Archaea and Eukarya		bio-classification
Domain Bacteria	Single-celled organisms without a nucleus, common everywhere		bio-classification
Domain Archaea	Single-celled organisms without a nucleus, often in extreme places		bio-classification
Domain Eukarya	Organisms whose cells have a nucleus		bio-classification
Kingdom Animalia	Multicellular organisms that eat food and can move		bio-classification
Kingdom Plantae	Multicellular organisms that make food by photosynthesis		bio-classification
Kingdom Fungi	Organisms that absorb food from their surroundings, like mushrooms		bio-classification
Kingdom Protista	Mostly single-celled eukaryotes, like amoebas and algae		bio-classification
Phylum Chordata	Animals with a backbone or notochord		bio-classification
Phylum Arthropoda	Animals with jointed legs and an exoskeleton		bio-classification
Phylum Mollusca	Soft-bodied animals, often with shells, like snails and clams		bio-classification
Phylum Annelida	Segmented worms like earthworms		bio-classification
Phylum Cnidaria	Animals with stinging cells like jellyfish and corals		bio-classification
Phylum Echinodermata	Spiny-skinned animals like sea stars		bio-classification
Phylum Porifera	Sponges		bio-classification
Phylum Platyhelminthes	Flatworms		bio-classification
Class Mammalia	Animals with hair that feed milk to their young		bio-classification
Class Aves	Birds		bio-classification
Class Reptilia	Reptiles		bio-classification
Class Amphibia	Amphibians		bio-classification
Class Insecta	Insects		bio-classification
Class Arachnida	Spiders, scorpions and ticks		bio-classification
Vertebrate	An animal with a backbone		bio-classification
Invertebrate	An animal without a backbone		bio-classification
Dichotomous key	A tool that identifies organisms with a series of two-choice questions		bio-classification
Cladogram	A branching diagram showing evolutionary relationships		bio-classification
Phylogeny	The evolutionary history of a group of organisms		bio-classification
Autotroph	An organism that makes its own food		bio-classification
Heterotroph	An organism that gets food from other organisms		bio-classification
Prokaryote	A cell with no nucleus		bio-classification
Eukaryote	A cell with a nucleus		bio-classification
Homologous structures	Body parts with a shared origin but different jobs, like a bat wing and human arm		bio-classification
Analogous structures	Parts with similar jobs but different origins, like bird and insect wings		bio-classification
Vestigial structure	A body part that has lost most of its original use		bio-classification
Species definition	A group that can breed and make fertile offspring		bio-classification
Hybrid example: mule	Offspring of a horse and a donkey, usually sterile		bio-classification
Warm-blooded (endotherm)	Keeps a steady body temperature using its own heat		bio-classification
Cold-blooded (ectotherm)	Body temperature depends on the surroundings		bio-classification
Monotreme	An egg-laying mammal, like the platypus		bio-classification
Marsupial	A mammal whose young develop mostly in a pouch, like a kangaroo		bio-classification
Placental mammal	A mammal whose young develop inside the mother before birth		bio-classification
Angiosperm	A flowering plant		bio-classification
Mycology	The study of fungi		bio-classification
Botany	The study of plants		bio-classification
Zoology	The study of animals		bio-classification
Microbiology	The study of microscopic organisms		bio-classification
Entomology	The study of insects		bio-classification
Ornithology	The study of birds		bio-classification
Herpetology	The study of reptiles and amphibians		bio-classification
Ichthyology	The study of fish		bio-classification
Mammalogy	The study of mammals		bio-classification
Ecosystem	Living things and their nonliving surroundings interacting		bio-ecology
Habitat	The place where an organism lives		bio-ecology
Niche	An organism's role and way of life in its ecosystem		bio-ecology
Population	All members of one species in an area		bio-ecology
Community	All the populations living in an area		bio-ecology
Biosphere	All the parts of Earth where life exists		bio-ecology
Biome	A large region defined by climate, plants and animals		bio-ecology
Biotic factor	A living part of an ecosystem		bio-ecology
Abiotic factor	A nonliving part, like sunlight or water		bio-ecology
Producer	An organism that makes its own food, like a plant		bio-ecology
Consumer	An organism that eats other organisms		bio-ecology
Herbivore	An animal that eats only plants		bio-ecology
Carnivore	An animal that eats only animals		bio-ecology
Omnivore	An animal that eats both plants and animals		bio-ecology
Decomposer	An organism that breaks down dead matter, like fungi		bio-ecology
Scavenger	An animal that eats dead animals it did not kill		bio-ecology
Predator	An animal that hunts other animals		bio-ecology
Prey	An animal that is hunted		bio-ecology
Food chain	A single path of energy from one organism to the next		bio-ecology
Food web	Many connected food chains		bio-ecology
Trophic level	A step in a food chain		bio-ecology
Energy pyramid	A diagram showing energy decreasing at each level		bio-ecology
How much energy passes to the next level, roughly?	About 10 percent		bio-ecology
Primary consumer	An herbivore that eats producers		bio-ecology
Secondary consumer	An animal that eats primary consumers		bio-ecology
Apex predator	A predator at the top of the food chain		bio-ecology
Symbiosis	A close relationship between two species		bio-ecology
Mutualism	Both species benefit		bio-ecology
Commensalism	One species benefits and the other is not affected		bio-ecology
Parasitism	One species benefits and the other is harmed		bio-ecology
Competition	Organisms using the same limited resources		bio-ecology
Carrying capacity	The most individuals an environment can support		bio-ecology
Limiting factor	Something that keeps a population from growing, like food		bio-ecology
Succession	The slow change in an ecosystem's community over time		bio-ecology
Primary succession	Life starting in a place with no soil, like new rock		bio-ecology
Secondary succession	Regrowth after a disturbance where soil remains		bio-ecology
Pioneer species	The first species to move into a new area		bio-ecology
Keystone species	A species that has a big effect on its ecosystem		bio-ecology
Invasive species	A non-native species that spreads and harms an ecosystem		bio-ecology
Native species	A species that naturally lives in an area		bio-ecology
Endangered species	A species at risk of dying out		bio-ecology
Extinct	No members of the species are left alive		bio-ecology
Biodiversity	The variety of life in an area		bio-ecology
Tundra	Cold, treeless biome with frozen ground		bio-ecology
Taiga (boreal forest)	Cold forest biome with evergreen trees		bio-ecology
Temperate forest	Forest with four seasons and deciduous trees		bio-ecology
Tropical rainforest	Warm, wet forest with the most species		bio-ecology
Grassland	Biome of grasses with few trees		bio-ecology
Savanna	Tropical grassland with scattered trees		bio-ecology
Desert	Biome that gets very little rain		bio-ecology
Wetland	Land covered with water for much of the year, like a marsh		bio-ecology
Estuary	Where a river meets the sea and fresh and salt water mix		bio-ecology
Coral reef	An underwater ecosystem built by coral animals		bio-ecology
Nitrogen cycle	How nitrogen moves between air, soil and living things		bio-ecology
Carbon cycle	How carbon moves between air, living things and Earth		bio-ecology
Water cycle	How water moves between Earth's surface and the air		bio-ecology
Nitrogen fixation	Bacteria turning nitrogen gas into a form plants can use		bio-ecology
Hibernation	A long winter sleep to save energy		bio-ecology
Migration	Moving from one region to another with the seasons		bio-ecology
Camouflage	Coloring that helps an organism blend into its surroundings		bio-ecology
Mimicry	When one species looks like another		bio-ecology
Estivation	A summer sleep to survive heat or drought		bio-ecology
Overpopulation	When there are too many individuals for the resources		bio-ecology
Ecological footprint	The amount of nature a person or group uses		bio-ecology
Heredity	Passing of traits from parents to offspring		bio-genetics-terms
Gene	A section of DNA that codes for a trait or protein		bio-genetics-terms
DNA	The molecule that carries genetic instructions (Deoxyribonucleic acid)		bio-genetics-terms
RNA	A molecule that helps carry out DNA's instructions		bio-genetics-terms
Chromosome	A packaged strand of DNA		bio-genetics-terms
How many chromosomes do humans have in body cells?	46 (23 pairs)		bio-genetics-terms
Allele	A version of a gene		bio-genetics-terms
Dominant allele	One that shows up when present		bio-genetics-terms
Recessive allele	One that shows only when two copies are present		bio-genetics-terms
Genotype	The set of alleles an organism has		bio-genetics-terms
Phenotype	The visible traits of an organism		bio-genetics-terms
Homozygous	Having two of the same allele		bio-genetics-terms
Heterozygous	Having two different alleles		bio-genetics-terms
Punnett square	A grid used to predict the results of a genetic cross		bio-genetics-terms
Trait	A characteristic passed from parent to child		bio-genetics-terms
Mutation	A change in DNA		bio-genetics-terms
Genome	All the DNA of an organism		bio-genetics-terms
Base pairs in DNA	A with T, and C with G		bio-genetics-terms
Adenine pairs with	Thymine in DNA		bio-genetics-terms
Cytosine pairs with	Guanine		bio-genetics-terms
In RNA, thymine is replaced by	Uracil		bio-genetics-terms
Nucleotide	A building block of DNA: sugar, phosphate and base		bio-genetics-terms
Double helix	The twisted-ladder shape of DNA		bio-genetics-terms
Who described the double helix in 1953?	James Watson and Francis Crick, using work by Rosalind Franklin		bio-genetics-terms
Who is the father of genetics?	Gregor Mendel		bio-genetics-terms
What did Mendel study?	Pea plants		bio-genetics-terms
Replication	Making a copy of DNA		bio-genetics-terms
Transcription	Copying DNA into messenger RNA		bio-genetics-terms
Translation	Reading mRNA to build a protein		bio-genetics-terms
Codon	Three bases in mRNA that code for one amino acid		bio-genetics-terms
Amino acid	A building block of protein		bio-genetics-terms
mRNA	Messenger RNA: carries a gene's message to the ribosome		bio-genetics-terms
tRNA	Transfer RNA: brings amino acids to the ribosome		bio-genetics-terms
Sex chromosomes	X and Y; they help determine sex		bio-genetics-terms
Autosome	A chromosome that is not a sex chromosome		bio-genetics-terms
Karyotype	A picture of all of an organism's chromosomes		bio-genetics-terms
Gamete	A sex cell: sperm or egg		bio-genetics-terms
Zygote	A fertilized egg cell		bio-genetics-terms
Diploid	Having two sets of chromosomes		bio-genetics-terms
Haploid	Having one set of chromosomes		bio-genetics-terms
Incomplete dominance	A blend of two alleles, like pink from red and white		bio-genetics-terms
Codominance	Both alleles show up fully		bio-genetics-terms
Polygenic trait	A trait controlled by many genes, like height		bio-genetics-terms
Sex-linked trait	A trait whose gene is on a sex chromosome		bio-genetics-terms
Carrier	A person who has one copy of a recessive allele but no symptoms		bio-genetics-terms
Pedigree	A chart showing how a trait passes through a family		bio-genetics-terms
Hybrid	Offspring of two different parent types		bio-genetics-terms
Purebred	An organism with identical alleles for a trait		bio-genetics-terms
Selective breeding	Choosing parents with wanted traits to breed		bio-genetics-terms
Genetic engineering	Changing an organism's DNA on purpose		bio-genetics-terms
Clone	An organism genetically identical to its parent		bio-genetics-terms
Biotechnology	Using living things to make products or solve problems		bio-genetics-terms
CRISPR	A tool for editing genes		bio-genetics-terms
PCR	A method that copies tiny amounts of DNA many times		bio-genetics-terms
Gel electrophoresis	A method that separates DNA pieces by size		bio-genetics-terms
Human Genome Project	An effort that mapped human DNA, completed in 2003		bio-genetics-terms
Law of segregation	Alleles separate when sex cells form		bio-genetics-terms
Law of independent assortment	Genes for different traits are passed on separately		bio-genetics-terms
Evolution by natural selection	Traits that help survival become more common over time		bio-genetics-terms
Adaptation	A trait that helps an organism survive		bio-genetics-terms
Variation	Differences among individuals of a species		bio-genetics-terms
Epigenetics	Changes in how genes are used without changing the DNA code		bio-genetics-terms
Locus	The position of a gene on a chromosome		bio-genetics-terms
Down syndrome	A condition caused by an extra copy of chromosome 21		bio-genetics-terms
Characteristics of living things	They grow, reproduce, use energy, respond to surroundings and are made of cells		bio-life-processes-evolution
Photosynthesis	Making sugar from light, water and carbon dioxide		bio-life-processes-evolution
Photosynthesis equation (words)	Carbon dioxide + water + light gives glucose + oxygen		bio-life-processes-evolution
Photosynthesis equation (formula)	6CO2 + 6H2O gives C6H12O6 + 6O2		bio-life-processes-evolution
Where does photosynthesis happen?	In chloroplasts		bio-life-processes-evolution
Light-dependent reactions	Capture light energy; happen in the thylakoids		bio-life-processes-evolution
Calvin cycle	Uses energy to build sugar from carbon dioxide; happens in the stroma		bio-life-processes-evolution
Cellular respiration	Breaking down glucose to release energy		bio-life-processes-evolution
Cellular respiration equation (words)	Glucose + oxygen gives carbon dioxide + water + energy		bio-life-processes-evolution
Where does cellular respiration happen?	Mostly in mitochondria		bio-life-processes-evolution
Glycolysis	The first step of respiration, splitting glucose in the cytoplasm		bio-life-processes-evolution
Aerobic respiration	Respiration that uses oxygen		bio-life-processes-evolution
Anaerobic respiration	Releasing energy without oxygen		bio-life-processes-evolution
Fermentation	Anaerobic energy release that makes lactic acid or alcohol		bio-life-processes-evolution
ATP	The energy currency molecule of cells		bio-life-processes-evolution
Autotroph	Makes its own food		bio-life-processes-evolution
Heterotroph	Gets food from other organisms		bio-life-processes-evolution
Producer	An autotroph at the base of a food chain		bio-life-processes-evolution
Digestion	Breaking food into small pieces the body can absorb		bio-life-processes-evolution
Excretion	Removing wastes from the body		bio-life-processes-evolution
Respiration vs breathing	Breathing moves air; respiration releases energy in cells		bio-life-processes-evolution
Homeostasis	Keeping a stable internal environment		bio-life-processes-evolution
Metabolism	All chemical reactions in an organism		bio-life-processes-evolution
Reproduction	Making new organisms		bio-life-processes-evolution
Asexual reproduction	One parent makes identical offspring		bio-life-processes-evolution
Sexual reproduction	Two parents' cells combine to make varied offspring		bio-life-processes-evolution
Budding	A new organism grows out of the parent, as in yeast and hydra		bio-life-processes-evolution
Binary fission	A cell splits in two, as in bacteria		bio-life-processes-evolution
Regeneration	Regrowing lost parts, as a starfish does		bio-life-processes-evolution
Stimulus	Something that causes a reaction		bio-life-processes-evolution
Response	A reaction to a stimulus		bio-life-processes-evolution
Growth	Increase in size and cell number		bio-life-processes-evolution
Development	Changes an organism goes through in its life		bio-life-processes-evolution
Evolution	Change in the traits of a population over generations		bio-life-processes-evolution
Natural selection	Organisms with helpful traits survive and reproduce more		bio-life-processes-evolution
Who wrote On the Origin of Species in 1859?	Charles Darwin		bio-life-processes-evolution
Where did Darwin study finches?	The Galapagos Islands		bio-life-processes-evolution
Survival of the fittest	Those best suited to their environment tend to leave more offspring		bio-life-processes-evolution
Variation	Differences among individuals		bio-life-processes-evolution
Inheritance	Passing traits to offspring		bio-life-processes-evolution
Adaptation	A trait that helps an organism survive and reproduce		bio-life-processes-evolution
Selective breeding	People choosing which animals or plants to breed		bio-life-processes-evolution
Artificial selection	Another name for selective breeding		bio-life-processes-evolution
Fossil record	Fossils showing how life has changed over time		bio-life-processes-evolution
Common ancestor	A shared ancestor of different species		bio-life-processes-evolution
Homologous structures	Parts of different species with similar bones, like a human arm and a whale flipper		bio-life-processes-evolution
Vestigial structure	A body part that has lost most of its function		bio-life-processes-evolution
Speciation	Formation of a new species		bio-life-processes-evolution
Extinction	Death of an entire species		bio-life-processes-evolution
Mass extinction	Many species die out in a short geologic time		bio-life-processes-evolution
Peppered moth	An example of natural selection in changing environments		bio-life-processes-evolution
Antibiotic resistance	Bacteria evolving to survive antibiotics		bio-life-processes-evolution
Gene pool	All the alleles in a population		bio-life-processes-evolution
Mutation	A change in DNA that may create new traits		bio-life-processes-evolution
Genetic drift	Chance changes in allele frequency, especially in small populations		bio-life-processes-evolution
Geologic time scale	A calendar of Earth's history in eras and periods		bio-life-processes-evolution
Age of Earth	About 4.5 billion years		bio-life-processes-evolution
Oldest known fossils of life, about	3.5 billion years old		bio-life-processes-evolution
Cambrian explosion	About 540 million years ago, when many animal groups appeared		bio-life-processes-evolution
Human origin region	Africa		bio-life-processes-evolution
Homo sapiens	The species of modern humans		bio-life-processes-evolution
Lucy	A famous Australopithecus fossil found in Ethiopia in 1974		bio-life-processes-evolution
Hominin	A human or humanlike relative		bio-life-processes-evolution
Transitional fossil	A fossil showing features of two groups		bio-life-processes-evolution
Archaeopteryx	A fossil with features of dinosaurs and birds		bio-life-processes-evolution
Tiktaalik	A fossil fish with limb-like fins, about 375 million years old		bio-life-processes-evolution
Evolution of whales	Whales came from land mammals with legs		bio-life-processes-evolution
Coevolution	Two species evolving in response to each other		bio-life-processes-evolution
Convergent evolution	Unrelated species evolve similar traits, as in sharks and dolphins		bio-life-processes-evolution
Microorganism	A living thing too small to see without a microscope		bio-microbes
Bacteria	Single-celled organisms with no nucleus; some are helpful, some cause disease		bio-microbes
Virus	A tiny particle that needs a host cell to reproduce		bio-microbes
Is a virus alive?	Scientists usually say no; it cannot reproduce on its own		bio-microbes
Fungus	An organism that absorbs nutrients, like mold or yeast		bio-microbes
Yeast	A single-celled fungus used in baking		bio-microbes
Mold	A fuzzy fungus that grows on food and damp places		bio-microbes
Mushroom	The fruiting body of some fungi		bio-microbes
Protist	A mostly single-celled eukaryote, like an amoeba		bio-microbes
Amoeba	A protist that moves with pseudopods		bio-microbes
Paramecium	A slipper-shaped protist covered in cilia		bio-microbes
Euglena	A protist that can make food and swim with a flagellum		bio-microbes
Algae	Simple organisms that make food from sunlight, found in water		bio-microbes
Plankton	Tiny organisms that drift in water		bio-microbes
Phytoplankton	Plant-like plankton that make food from sunlight		bio-microbes
Zooplankton	Animal-like plankton		bio-microbes
Pathogen	A germ that causes disease		bio-microbes
Infection	When germs enter the body and multiply		bio-microbes
Antibiotic	Medicine that kills bacteria		bio-microbes
Do antibiotics work on viruses?	No		bio-microbes
Vaccine	Prepares the body to fight a specific germ		bio-microbes
Antibody	A protein the body makes to attack a germ		bio-microbes
Immunity	The body's ability to resist a disease		bio-microbes
Contagious	Able to spread from one person to another		bio-microbes
Quarantine	Keeping sick people apart to stop disease from spreading		bio-microbes
Sterilize	Kill all microbes on an object		bio-microbes
Pasteurization	Heating a food to kill harmful germs		bio-microbes
Who developed pasteurization and early vaccines?	Louis Pasteur		bio-microbes
Who discovered penicillin in 1928?	Alexander Fleming		bio-microbes
Who first built a smallpox vaccine in 1796?	Edward Jenner		bio-microbes
Germ theory	The idea that microbes cause many diseases		bio-microbes
Fermentation	Microbes turning sugars into other substances, as in bread and yogurt		bio-microbes
Probiotic	Helpful bacteria that live in the gut and some foods		bio-microbes
Gut bacteria	Helpful microbes in the intestines that help digest food		bio-microbes
Decomposers	Microbes and fungi that break down dead things		bio-microbes
Binary fission	How bacteria reproduce by splitting in two		bio-microbes
Capsid	The protein coat of a virus		bio-microbes
Host	An organism a germ or parasite lives in or on		bio-microbes
Parasite	An organism that lives on or in another and harms it		bio-microbes
Tapeworm	A parasite that lives in intestines		bio-microbes
Tick	A tiny arachnid that can carry germs		bio-microbes
Mosquito-borne disease: malaria	Caused by a parasite spread by mosquitoes		bio-microbes
Strep throat	An illness caused by bacteria		bio-microbes
Common cold	An illness caused by viruses		bio-microbes
Influenza	The flu, caused by a virus		bio-microbes
Athlete's foot	A skin infection caused by a fungus		bio-microbes
Why wash hands?	Soap lifts germs off the skin so they rinse away		bio-microbes
How should you cover a cough?	Into your elbow or a tissue		bio-microbes
Petri dish	Dish used to grow microbes in labs		bio-microbes
Agar	Jelly-like food used to grow microbes in a dish		bio-microbes
Colony	A visible group of microbes grown from one cell		bio-microbes
Spirillum	A spiral-shaped bacterium		bio-microbes
Bacillus	A rod-shaped bacterium		bio-microbes
Coccus	A round bacterium		bio-microbes
Lichen	A partnership between a fungus and an alga		bio-microbes
Mycorrhiza	A partnership between fungus and plant roots		bio-microbes
Penicillium	A mold that gave us the first antibiotic		bio-microbes
Flagellum on bacteria	A whip-like tail used to swim		bio-microbes
Spore	A tough cell that survives bad conditions and can grow later		bio-microbes
Endospore	A hardy dormant form made by some bacteria		bio-microbes
Epidemic	A disease that spreads quickly in a community		bio-microbes
Pandemic	A disease that spreads across many countries		bio-microbes
Biceps brachii	Front of the upper arm; bends the elbow		bio-muscles
Triceps brachii	Back of the upper arm; straightens the elbow		bio-muscles
Deltoid	Shoulder muscle that lifts the arm		bio-muscles
Pectoralis major	Large chest muscle		bio-muscles
Latissimus dorsi	Broad muscle of the back		bio-muscles
Trapezius	Muscle across the upper back and neck		bio-muscles
Abdominals	Muscles of the belly that help the trunk bend and twist		bio-muscles
Gluteus maximus	The largest muscle in the body, in the buttock		bio-muscles
Quadriceps	Four muscles at the front of the thigh that straighten the knee		bio-muscles
Hamstrings	Muscles at the back of the thigh that bend the knee		bio-muscles
Gastrocnemius	The big calf muscle		bio-muscles
Soleus	Calf muscle lying below the gastrocnemius		bio-muscles
Tibialis anterior	Muscle on the front of the shin		bio-muscles
Sartorius	Long strap-like muscle of the thigh		bio-muscles
Masseter	Chewing muscle in the jaw		bio-muscles
Orbicularis oculi	Muscle that closes the eyelids		bio-muscles
Diaphragm	Muscle that helps you breathe		bio-muscles
Intercostals	Muscles between the ribs		bio-muscles
Rotator cuff	Group of shoulder muscles that stabilize the joint		bio-muscles
Achilles tendon	Strong tendon that connects the calf muscles to the heel		bio-muscles
Skeletal muscle	Voluntary muscle attached to bones; striped		bio-muscles
Smooth muscle	Involuntary muscle in organs such as the stomach		bio-muscles
Cardiac muscle	Muscle of the heart		bio-muscles
Voluntary muscle	One you can control		bio-muscles
Involuntary muscle	One that works without you thinking		bio-muscles
Tendon	Connects muscle to bone		bio-muscles
Ligament	Connects bone to bone		bio-muscles
Contraction	When a muscle shortens		bio-muscles
Muscles can only	Pull; they cannot push		bio-muscles
Antagonistic pair	Two muscles that work in opposite ways, like biceps and triceps		bio-muscles
Flexor	A muscle that bends a joint		bio-muscles
Extensor	A muscle that straightens a joint		bio-muscles
Muscle fiber	A long muscle cell		bio-muscles
Myofibril	Thread-like part inside a muscle fiber that contracts		bio-muscles
Actin and myosin	Proteins that slide to make muscles contract		bio-muscles
ATP	The energy molecule muscles use		bio-muscles
Lactic acid	A by-product that can build up in tired muscles		bio-muscles
Muscle tone	The small constant tension in resting muscles		bio-muscles
Atrophy	Muscle shrinking from not being used		bio-muscles
Hypertrophy	Muscle growing larger from use		bio-muscles
Cramp	A sudden painful tightening of a muscle		bio-muscles
Sprain	An injury that stretches or tears a ligament		bio-muscles
Strain	An injury that stretches or tears a muscle or tendon		bio-muscles
Warm up	Gentle exercise before activity to prepare muscles		bio-muscles
Protein	A nutrient that helps build and repair muscle		bio-muscles
Fast-twitch fibers	Muscle fibers that contract quickly for sprints		bio-muscles
Slow-twitch fibers	Muscle fibers that work for a long time without tiring		bio-muscles
How many muscles do people have, about?	More than 600		bio-muscles
Which muscle in the body never rests?	The heart		bio-muscles
Neuromuscular junction	Where a nerve meets a muscle to tell it to contract		bio-muscles
Extraocular muscles	The six muscles that move each eye		bio-muscles
Sphincter	A ring-shaped muscle that opens and closes an opening		bio-muscles
Peristalsis	Waves of smooth muscle squeezing food along		bio-muscles
Sarcomere	The basic contracting unit of a muscle fiber		bio-muscles
Roots	Anchor the plant and take in water and minerals		bio-plants
Stem	Holds the plant up and carries water and food		bio-plants
Leaf	The main place where a plant makes food		bio-plants
Flower	The part of a plant that makes seeds		bio-plants
Fruit	A ripened ovary that holds seeds		bio-plants
Seed	Holds a baby plant and food to start growing		bio-plants
Petal	Colorful part of a flower that attracts pollinators		bio-plants
Sepal	Green leaf-like part that protects a flower bud		bio-plants
Stamen	Male part of a flower that makes pollen		bio-plants
Anther	Top of the stamen that holds pollen		bio-plants
Filament	The stalk that holds up the anther		bio-plants
Pistil	Female part of a flower		bio-plants
Stigma	Sticky top of the pistil that catches pollen		bio-plants
Style	Tube that connects the stigma to the ovary		bio-plants
Ovary	Part of the pistil that holds the ovules		bio-plants
Ovule	Part of the ovary that becomes a seed		bio-plants
Pollen	Tiny grains that carry male cells of plants		bio-plants
Pollination	Moving pollen to the female part of a flower		bio-plants
Pollinator	An animal such as a bee that moves pollen		bio-plants
Fertilization	When male and female cells join to start a seed		bio-plants
Germination	When a seed begins to grow		bio-plants
Photosynthesis	Plants turn light, water and carbon dioxide into sugar and oxygen		bio-plants
Chlorophyll	Green pigment that captures light		bio-plants
Stomata	Tiny leaf openings that let gases in and out		bio-plants
Guard cells	Cells that open and close the stomata		bio-plants
Transpiration	Water evaporating from leaves		bio-plants
Xylem	Tubes that carry water up from the roots		bio-plants
Phloem	Tubes that carry sugar through the plant		bio-plants
Taproot	One thick main root, like a carrot		bio-plants
Fibrous roots	Many thin roots, like grass		bio-plants
Root hairs	Tiny extensions that absorb water		bio-plants
Cotyledon	A seed leaf that stores food in the seed		bio-plants
Monocot	A flowering plant with one seed leaf, like corn and grass		bio-plants
Dicot	A flowering plant with two seed leaves, like beans		bio-plants
Angiosperm	A plant that makes flowers and fruits		bio-plants
Gymnosperm	A plant with seeds not in fruit, like pine trees		bio-plants
Conifer	A tree that makes cones, such as pine or spruce		bio-plants
Deciduous	A tree that loses its leaves each fall		bio-plants
Evergreen	A plant that keeps green leaves all year		bio-plants
Annual	A plant that lives one growing season		bio-plants
Biennial	A plant that lives two years		bio-plants
Perennial	A plant that lives for many years		bio-plants
Vascular plant	A plant with tubes for carrying water and food		bio-plants
Nonvascular plant	A plant without such tubes, like moss		bio-plants
Spore	A tiny cell that can grow into a new fungus or fern or moss		bio-plants
Fern	A plant with fronds that reproduces with spores		bio-plants
Moss	A small nonvascular plant that grows in damp places		bio-plants
Tropism	A plant's growth response to something like light or gravity		bio-plants
Phototropism	Growing toward light		bio-plants
Gravitropism	Roots growing down and shoots growing up in response to gravity		bio-plants
Dormancy	A resting period when growth slows		bio-plants
Seed dispersal	How seeds travel away from the parent plant		bio-plants
Bulb	An underground storage stem, like an onion or tulip		bio-plants
Tuber	A thick underground stem, like a potato		bio-plants
Rhizome	An underground stem that spreads sideways		bio-plants
Cambium	A thin growing layer that makes new wood and bark		bio-plants
Tree rings	Rings in a trunk showing one year of growth each		bio-plants
Heartwood	The old, dense center of a tree trunk		bio-plants
Bark	The protective outer covering of a tree		bio-plants
Carnivorous plant	A plant that traps and digests insects, like a Venus flytrap		bio-plants
Parasitic plant	A plant that takes food from another plant		bio-plants
Epiphyte	A plant that grows on another plant without harming it		bio-plants
Compost	Decayed plant matter that enriches soil		bio-plants
Nitrogen, phosphorus and potassium	The main nutrients in fertilizer		bio-plants
What do plants release during photosynthesis?	Oxygen		bio-plants
What do plants take in from air for photosynthesis?	Carbon dioxide		bio-plants
Why are leaves green?	They contain chlorophyll		bio-plants
Why do leaves change color in fall?	Chlorophyll breaks down and other colors show		bio-plants
Sap	Fluid that moves through a plant		bio-plants
What do we use to see?	Eyes		bio-senses-and-organs
What do we use to hear?	Ears		bio-senses-and-organs
What do we use to smell?	Nose		bio-senses-and-organs
What do we use to taste?	Tongue		bio-senses-and-organs
What do we use to feel and touch?	Skin		bio-senses-and-organs
How many senses do we have (the basic ones)?	Five		bio-senses-and-organs
What are the five senses?	Sight, hearing, smell, taste and touch		bio-senses-and-organs
What pumps blood around the body?	The heart		bio-senses-and-organs
What do we use to breathe?	Lungs		bio-senses-and-organs
What is the control center of the body?	The brain		bio-senses-and-organs
Where does food go after we swallow it?	To the stomach		bio-senses-and-organs
What protects our brain?	The skull		bio-senses-and-organs
What holds us up inside?	Our bones		bio-senses-and-organs
What do muscles do?	Help us move		bio-senses-and-organs
What covers our body?	Skin		bio-senses-and-organs
What do teeth do?	Bite and chew food		bio-senses-and-organs
What does the tongue taste?	Sweet, sour, salty, bitter and savory		bio-senses-and-organs
What part of the eye lets light in?	The pupil		bio-senses-and-organs
What is the colored part of the eye?	The iris		bio-senses-and-organs
What do eyelashes do?	Keep dust out of the eyes		bio-senses-and-organs
What part of the ear can we see?	The outer ear		bio-senses-and-organs
What helps you hear sounds?	Eardrum and tiny bones in the ear		bio-senses-and-organs
Which sense uses the nose?	Smell		bio-senses-and-organs
Which sense uses the tongue?	Taste		bio-senses-and-organs
What is the hardest part of the body?	Tooth enamel		bio-senses-and-organs
How many fingers on two hands?	Ten		bio-senses-and-organs
What happens to baby teeth?	They fall out and adult teeth grow in		bio-senses-and-organs
How many teeth do adults usually have?	32, including wisdom teeth		bio-senses-and-organs
What helps you stay healthy: sleep, food and what else?	Exercise		bio-senses-and-organs
What do we wash with soap to get rid of germs?	Hands		bio-senses-and-organs
What does a doctor use to listen to your heart?	A stethoscope		bio-senses-and-organs
What makes you sneeze?	Your nose clearing out dust or germs		bio-senses-and-organs
What are goosebumps?	Skin bumps from tiny muscles pulling hairs up		bio-senses-and-organs
Why do we sweat?	To cool the body down		bio-senses-and-organs
What is a pulse?	The beat of your heart you can feel in your wrist		bio-senses-and-organs
What fills your lungs when you breathe in?	Air		bio-senses-and-organs
What gas do we breathe out?	Carbon dioxide		bio-senses-and-organs
What gas do we need to breathe in?	Oxygen		bio-senses-and-organs
What do our ears help us do besides hear?	Keep our balance		bio-senses-and-organs
How do we feel hot or cold?	Nerves in the skin sense it		bio-senses-and-organs
Which sense do we use to feel a soft blanket?	Touch		bio-senses-and-organs
Which sense do we use to enjoy music?	Hearing		bio-senses-and-organs
Which sense do we use to read a book?	Sight		bio-senses-and-organs
Which part of the body helps us think?	The brain		bio-senses-and-organs
What is the biggest organ you can see?	Skin		bio-senses-and-organs
What do we call the bones in your back?	Spine		bio-senses-and-organs
What are the bendy places on your arm and leg?	Joints, like elbows and knees		bio-senses-and-organs
What do eyebrows do?	Help keep sweat out of your eyes		bio-senses-and-organs
What do fingernails do?	Protect the tips of fingers		bio-senses-and-organs
What helps blood move through the body?	Heart and blood vessels		bio-senses-and-organs
What does pH measure?	How acidic or basic a solution is		chem-acids-bases
pH range of the common scale	0 to 14		chem-acids-bases
pH of a neutral solution	7		chem-acids-bases
Acids have a pH	Less than 7		chem-acids-bases
Bases have a pH	Greater than 7		chem-acids-bases
pH of pure water	7		chem-acids-bases
Taste of acids	Sour (never taste in lab)		chem-acids-bases
Feel of bases	Slippery (never touch unknown ones)		chem-acids-bases
Taste of bases	Bitter		chem-acids-bases
Litmus paper in acid	Turns red		chem-acids-bases
Litmus paper in base	Turns blue		chem-acids-bases
Phenolphthalein in base	Turns pink		chem-acids-bases
Universal indicator	Changes color across the pH scale		chem-acids-bases
Indicator	A substance that changes color to show acidity or basicity		chem-acids-bases
Neutralization	An acid and a base react to form water and a salt		chem-acids-bases
Salt (in chemistry)	An ionic compound made when an acid reacts with a base		chem-acids-bases
Lemon juice	An acid, pH about 2		chem-acids-bases
Vinegar	An acid, containing acetic acid		chem-acids-bases
Stomach acid	Hydrochloric acid, very strong		chem-acids-bases
Baking soda	A weak base		chem-acids-bases
Soap	A base; it feels slippery		chem-acids-bases
Ammonia cleaner	A base		chem-acids-bases
Bleach	A strong base, pH about 12 to 13; do not mix with other cleaners		chem-acids-bases
Milk	Nearly neutral, slightly acidic		chem-acids-bases
Black coffee	A weak acid		chem-acids-bases
Orange juice	An acid, pH about 3 to 4		chem-acids-bases
Antacid	A base that neutralizes extra stomach acid		chem-acids-bases
Citric acid	The acid in lemons and oranges		chem-acids-bases
Carbonic acid	A weak acid in fizzy drinks		chem-acids-bases
Sulfuric acid	A strong acid used in car batteries and industry		chem-acids-bases
Hydrochloric acid	A strong acid, formula HCl		chem-acids-bases
Sodium hydroxide	A strong base, formula NaOH, also called lye		chem-acids-bases
Each step on the pH scale	Is ten times stronger or weaker than the next		chem-acids-bases
Which is more acidic, pH 3 or pH 5?	pH 3, a hundred times more acidic		chem-acids-bases
Strong acid	An acid that breaks apart fully in water		chem-acids-bases
Weak acid	An acid that only partly breaks apart in water		chem-acids-bases
Alkaline	Another word for basic		chem-acids-bases
Corrosive	Able to eat away at materials		chem-acids-bases
Acid rain	Rain made acidic by pollution, with pH below about 5.6		chem-acids-bases
H+	The hydrogen ion that acids release in water		chem-acids-bases
OH-	The hydroxide ion that bases release in water		chem-acids-bases
Hydronium	H3O+, formed when an acid adds H+ to water		chem-acids-bases
Buffer	A solution that resists changes in pH		chem-acids-bases
Titration	Adding a solution of known strength drop by drop to find an unknown concentration		chem-acids-bases
pH of blood	About 7.4, slightly basic		chem-acids-bases
Red cabbage juice	A natural indicator that changes color with pH		chem-acids-bases
Mixing vinegar and baking soda makes	Carbon dioxide gas, which fizzes		chem-acids-bases
Do acids conduct electricity in water?	Yes, because they form ions		chem-acids-bases
Which acid is in ant stings?	Formic acid		chem-acids-bases
Which acid is in vinegar?	Acetic acid		chem-acids-bases
Which acid is in yogurt and sour milk?	Lactic acid		chem-acids-bases
Which acid is in our muscles after hard exercise?	Lactic acid		chem-acids-bases
Which scientist invented the pH scale in 1909?	Soren Sorensen		chem-acids-bases
1	Hydrogen (H)		chem-atomic-numbers-1-30
2	Helium (He)		chem-atomic-numbers-1-30
3	Lithium (Li)		chem-atomic-numbers-1-30
4	Beryllium (Be)		chem-atomic-numbers-1-30
5	Boron (B)		chem-atomic-numbers-1-30
6	Carbon (C)		chem-atomic-numbers-1-30
7	Nitrogen (N)		chem-atomic-numbers-1-30
8	Oxygen (O)		chem-atomic-numbers-1-30
9	Fluorine (F)		chem-atomic-numbers-1-30
10	Neon (Ne)		chem-atomic-numbers-1-30
11	Sodium (Na)		chem-atomic-numbers-1-30
12	Magnesium (Mg)		chem-atomic-numbers-1-30
13	Aluminum (Al)		chem-atomic-numbers-1-30
14	Silicon (Si)		chem-atomic-numbers-1-30
15	Phosphorus (P)		chem-atomic-numbers-1-30
16	Sulfur (S)		chem-atomic-numbers-1-30
17	Chlorine (Cl)		chem-atomic-numbers-1-30
18	Argon (Ar)		chem-atomic-numbers-1-30
19	Potassium (K)		chem-atomic-numbers-1-30
20	Calcium (Ca)		chem-atomic-numbers-1-30
21	Scandium (Sc)		chem-atomic-numbers-1-30
22	Titanium (Ti)		chem-atomic-numbers-1-30
23	Vanadium (V)		chem-atomic-numbers-1-30
24	Chromium (Cr)		chem-atomic-numbers-1-30
25	Manganese (Mn)		chem-atomic-numbers-1-30
26	Iron (Fe)		chem-atomic-numbers-1-30
27	Cobalt (Co)		chem-atomic-numbers-1-30
28	Nickel (Ni)		chem-atomic-numbers-1-30
29	Copper (Cu)		chem-atomic-numbers-1-30
30	Zinc (Zn)		chem-atomic-numbers-1-30
31	Gallium (Ga)		chem-atomic-numbers-31-60
32	Germanium (Ge)		chem-atomic-numbers-31-60
33	Arsenic (As)		chem-atomic-numbers-31-60
34	Selenium (Se)		chem-atomic-numbers-31-60
35	Bromine (Br)		chem-atomic-numbers-31-60
36	Krypton (Kr)		chem-atomic-numbers-31-60
37	Rubidium (Rb)		chem-atomic-numbers-31-60
38	Strontium (Sr)		chem-atomic-numbers-31-60
39	Yttrium (Y)		chem-atomic-numbers-31-60
40	Zirconium (Zr)		chem-atomic-numbers-31-60
41	Niobium (Nb)		chem-atomic-numbers-31-60
42	Molybdenum (Mo)		chem-atomic-numbers-31-60
43	Technetium (Tc)		chem-atomic-numbers-31-60
44	Ruthenium (Ru)		chem-atomic-numbers-31-60
45	Rhodium (Rh)		chem-atomic-numbers-31-60
46	Palladium (Pd)		chem-atomic-numbers-31-60
47	Silver (Ag)		chem-atomic-numbers-31-60
48	Cadmium (Cd)		chem-atomic-numbers-31-60
49	Indium (In)		chem-atomic-numbers-31-60
50	Tin (Sn)		chem-atomic-numbers-31-60
51	Antimony (Sb)		chem-atomic-numbers-31-60
52	Tellurium (Te)		chem-atomic-numbers-31-60
53	Iodine (I)		chem-atomic-numbers-31-60
54	Xenon (Xe)		chem-atomic-numbers-31-60
55	Cesium (Cs)		chem-atomic-numbers-31-60
56	Barium (Ba)		chem-atomic-numbers-31-60
57	Lanthanum (La)		chem-atomic-numbers-31-60
58	Cerium (Ce)		chem-atomic-numbers-31-60
59	Praseodymium (Pr)		chem-atomic-numbers-31-60
60	Neodymium (Nd)		chem-atomic-numbers-31-60
61	Promethium (Pm)		chem-atomic-numbers-61-90
62	Samarium (Sm)		chem-atomic-numbers-61-90
63	Europium (Eu)		chem-atomic-numbers-61-90
64	Gadolinium (Gd)		chem-atomic-numbers-61-90
65	Terbium (Tb)		chem-atomic-numbers-61-90
66	Dysprosium (Dy)		chem-atomic-numbers-61-90
67	Holmium (Ho)		chem-atomic-numbers-61-90
68	Erbium (Er)		chem-atomic-numbers-61-90
69	Thulium (Tm)		chem-atomic-numbers-61-90
70	Ytterbium (Yb)		chem-atomic-numbers-61-90
71	Lutetium (Lu)		chem-atomic-numbers-61-90
72	Hafnium (Hf)		chem-atomic-numbers-61-90
73	Tantalum (Ta)		chem-atomic-numbers-61-90
74	Tungsten (W)		chem-atomic-numbers-61-90
75	Rhenium (Re)		chem-atomic-numbers-61-90
76	Osmium (Os)		chem-atomic-numbers-61-90
77	Iridium (Ir)		chem-atomic-numbers-61-90
78	Platinum (Pt)		chem-atomic-numbers-61-90
79	Gold (Au)		chem-atomic-numbers-61-90
80	Mercury (Hg)		chem-atomic-numbers-61-90
81	Thallium (Tl)		chem-atomic-numbers-61-90
82	Lead (Pb)		chem-atomic-numbers-61-90
83	Bismuth (Bi)		chem-atomic-numbers-61-90
84	Polonium (Po)		chem-atomic-numbers-61-90
85	Astatine (At)		chem-atomic-numbers-61-90
86	Radon (Rn)		chem-atomic-numbers-61-90
87	Francium (Fr)		chem-atomic-numbers-61-90
88	Radium (Ra)		chem-atomic-numbers-61-90
89	Actinium (Ac)		chem-atomic-numbers-61-90
90	Thorium (Th)		chem-atomic-numbers-61-90
91	Protactinium (Pa)		chem-atomic-numbers-91-118
92	Uranium (U)		chem-atomic-numbers-91-118
93	Neptunium (Np)		chem-atomic-numbers-91-118
94	Plutonium (Pu)		chem-atomic-numbers-91-118
95	Americium (Am)		chem-atomic-numbers-91-118
96	Curium (Cm)		chem-atomic-numbers-91-118
97	Berkelium (Bk)		chem-atomic-numbers-91-118
98	Californium (Cf)		chem-atomic-numbers-91-118
99	Einsteinium (Es)		chem-atomic-numbers-91-118
100	Fermium (Fm)		chem-atomic-numbers-91-118
101	Mendelevium (Md)		chem-atomic-numbers-91-118
102	Nobelium (No)		chem-atomic-numbers-91-118
103	Lawrencium (Lr)		chem-atomic-numbers-91-118
104	Rutherfordium (Rf)		chem-atomic-numbers-91-118
105	Dubnium (Db)		chem-atomic-numbers-91-118
106	Seaborgium (Sg)		chem-atomic-numbers-91-118
107	Bohrium (Bh)		chem-atomic-numbers-91-118
108	Hassium (Hs)		chem-atomic-numbers-91-118
109	Meitnerium (Mt)		chem-atomic-numbers-91-118
110	Darmstadtium (Ds)		chem-atomic-numbers-91-118
111	Roentgenium (Rg)		chem-atomic-numbers-91-118
112	Copernicium (Cn)		chem-atomic-numbers-91-118
113	Nihonium (Nh)		chem-atomic-numbers-91-118
114	Flerovium (Fl)		chem-atomic-numbers-91-118
115	Moscovium (Mc)		chem-atomic-numbers-91-118
116	Livermorium (Lv)		chem-atomic-numbers-91-118
117	Tennessine (Ts)		chem-atomic-numbers-91-118
118	Oganesson (Og)		chem-atomic-numbers-91-118
Atom	The smallest unit of an element that still has its properties		chem-basic-terms
Molecule	Two or more atoms joined together		chem-basic-terms
Element	A pure substance made of only one kind of atom		chem-basic-terms
Compound	A substance made of two or more elements chemically joined		chem-basic-terms
Mixture	Two or more substances together but not chemically joined		chem-basic-terms
Proton	Positive particle in the nucleus		chem-basic-terms
Neutron	Particle with no charge in the nucleus		chem-basic-terms
Electron	Tiny negative particle that moves around the nucleus		chem-basic-terms
Nucleus	The center of an atom, holding protons and neutrons		chem-basic-terms
Ion	An atom or group of atoms with an electric charge		chem-basic-terms
Cation	A positive ion		chem-basic-terms
Anion	A negative ion		chem-basic-terms
Ionic bond	A bond formed when electrons move from one atom to another		chem-basic-terms
Covalent bond	A bond formed when atoms share electrons		chem-basic-terms
Metallic bond	A bond in which electrons flow freely among metal atoms		chem-basic-terms
Chemical formula	Symbols and numbers showing what atoms make up a substance		chem-basic-terms
Chemical reaction	A process in which substances change into new substances		chem-basic-terms
Reactant	A starting substance in a chemical reaction		chem-basic-terms
Product	A substance made by a chemical reaction		chem-basic-terms
Chemical equation	A way to show a reaction using formulas		chem-basic-terms
Law of conservation of mass	Matter is not created or destroyed in a chemical reaction		chem-basic-terms
Catalyst	A substance that speeds up a reaction without being used up		chem-basic-terms
Enzyme	A biological catalyst, made of protein		chem-basic-terms
Solution	A mixture that is the same all the way through		chem-basic-terms
Solute	The substance that is dissolved		chem-basic-terms
Solvent	The substance that does the dissolving		chem-basic-terms
Solubility	How much of a substance can dissolve in a solvent		chem-basic-terms
Concentration	How much solute is in a certain amount of solution		chem-basic-terms
Saturated solution	One that cannot dissolve any more solute		chem-basic-terms
Suspension	A mixture with particles that settle out if left alone		chem-basic-terms
Colloid	A mixture with tiny particles that stay spread out, like milk		chem-basic-terms
Density	How much mass is in a given volume		chem-basic-terms
Mass	The amount of matter in an object		chem-basic-terms
Volume	The amount of space something takes up		chem-basic-terms
Physical change	A change in form that does not make a new substance		chem-basic-terms
Chemical change	A change that makes new substances		chem-basic-terms
Physical property	A trait you can observe without changing the substance, like color		chem-basic-terms
Chemical property	How a substance can change into another, like flammability		chem-basic-terms
Exothermic reaction	A reaction that gives off heat		chem-basic-terms
Endothermic reaction	A reaction that takes in heat		chem-basic-terms
Oxidation	A reaction in which a substance loses electrons or combines with oxygen		chem-basic-terms
Reduction	A reaction in which a substance gains electrons		chem-basic-terms
Precipitate	A solid that forms from a liquid solution during a reaction		chem-basic-terms
Distillation	Separating liquids by boiling and condensing them		chem-basic-terms
Filtration	Separating solids from liquids using a filter		chem-basic-terms
Evaporation	A liquid changing to a gas at its surface		chem-basic-terms
Condensation	A gas changing into a liquid		chem-basic-terms
Mole	A unit for counting atoms: 6.02 x 10^23 particles		chem-basic-terms
Avogadro's number	6.02 x 10^23, the number of particles in one mole		chem-basic-terms
Molar mass	The mass of one mole of a substance		chem-basic-terms
Valence electron	An electron in the outer shell that takes part in bonding		chem-basic-terms
Atomic number	Number of protons in an atom		chem-basic-terms
Mass number	Protons plus neutrons in an atom		chem-basic-terms
Isotope	Atoms of one element with different numbers of neutrons		chem-basic-terms
Radioactivity	The giving off of energy and particles by unstable atoms		chem-basic-terms
Half-life	Time it takes half of a radioactive sample to decay		chem-basic-terms
Polymer	A large molecule made of many repeating units		chem-basic-terms
Organic compound	A compound built on carbon, usually with hydrogen		chem-basic-terms
Allotrope	One of different forms of the same element, like diamond and graphite		chem-basic-terms
Alloy	A mixture of metals, such as brass or steel		chem-basic-terms
Corrosion	The slow wearing away of metal by chemical reaction		chem-basic-terms
Combustion	Burning: a fast reaction of a fuel with oxygen		chem-basic-terms
Synthesis reaction	Two or more substances combine to make one product		chem-basic-terms
Decomposition reaction	One compound breaks down into simpler substances		chem-basic-terms
Electrolysis	Using electricity to split a compound		chem-basic-terms
Inert	Not reacting easily with other substances		chem-basic-terms
Reactivity	How easily a substance takes part in chemical reactions		chem-basic-terms
Malleable	Able to be hammered into thin sheets		chem-basic-terms
Ductile	Able to be pulled into wire		chem-basic-terms
Conductor	A material that lets heat or electricity flow easily		chem-basic-terms
Insulator	A material that does not let heat or electricity flow easily		chem-basic-terms
Electronegativity	How strongly an atom pulls on shared electrons		chem-basic-terms
Periodic law	Element properties repeat in a pattern as atomic number goes up		chem-basic-terms
Water	H2O		chem-compound-formulas
Carbon dioxide	CO2		chem-compound-formulas
Carbon monoxide	CO		chem-compound-formulas
Oxygen gas	O2		chem-compound-formulas
Hydrogen gas	H2		chem-compound-formulas
Nitrogen gas	N2		chem-compound-formulas
Ozone	O3		chem-compound-formulas
Table salt (sodium chloride)	NaCl		chem-compound-formulas
Hydrogen peroxide	H2O2		chem-compound-formulas
Methane	CH4		chem-compound-formulas
Ethane	C2H6		chem-compound-formulas
Propane	C3H8		chem-compound-formulas
Butane	C4H10		chem-compound-formulas
Ethanol	C2H5OH		chem-compound-formulas
Glucose	C6H12O6		chem-compound-formulas
Sucrose (table sugar)	C12H22O11		chem-compound-formulas
Ammonia	NH3		chem-compound-formulas
Ammonium ion	NH4+		chem-compound-formulas
Hydrochloric acid	HCl		chem-compound-formulas
Sulfuric acid	H2SO4		chem-compound-formulas
Nitric acid	HNO3		chem-compound-formulas
Acetic acid	CH3COOH		chem-compound-formulas
Carbonic acid	H2CO3		chem-compound-formulas
Phosphoric acid	H3PO4		chem-compound-formulas
Sodium hydroxide	NaOH		chem-compound-formulas
Potassium hydroxide	KOH		chem-compound-formulas
Calcium hydroxide	Ca(OH)2		chem-compound-formulas
Calcium carbonate (limestone, chalk)	CaCO3		chem-compound-formulas
Sodium bicarbonate (baking soda)	NaHCO3		chem-compound-formulas
Sodium carbonate (washing soda)	Na2CO3		chem-compound-formulas
Calcium oxide (quicklime)	CaO		chem-compound-formulas
Magnesium oxide	MgO		chem-compound-formulas
Iron(III) oxide (rust)	Fe2O3		chem-compound-formulas
Aluminum oxide	Al2O3		chem-compound-formulas
Silicon dioxide (quartz, sand)	SiO2		chem-compound-formulas
Sulfur dioxide	SO2		chem-compound-formulas
Nitrogen dioxide	NO2		chem-compound-formulas
Nitrous oxide (laughing gas)	N2O		chem-compound-formulas
Sodium nitrate	NaNO3		chem-compound-formulas
Potassium chloride	KCl		chem-compound-formulas
Calcium chloride	CaCl2		chem-compound-formulas
Magnesium sulfate (Epsom salt)	MgSO4		chem-compound-formulas
Copper sulfate	CuSO4		chem-compound-formulas
Silver nitrate	AgNO3		chem-compound-formulas
Potassium permanganate	KMnO4		chem-compound-formulas
Sodium hypochlorite (bleach)	NaOCl		chem-compound-formulas
Calcium sulfate (gypsum)	CaSO4		chem-compound-formulas
Zinc oxide	ZnO		chem-compound-formulas
Hydrogen sulfide	H2S		chem-compound-formulas
Hydrogen fluoride	HF		chem-compound-formulas
Lithium fluoride	LiF		chem-compound-formulas
Potassium iodide	KI		chem-compound-formulas
Titanium dioxide	TiO2		chem-compound-formulas
Acetylene	C2H2		chem-compound-formulas
Ethylene	C2H4		chem-compound-formulas
Benzene	C6H6		chem-compound-formulas
Urea	CH4N2O or (NH2)2CO		chem-compound-formulas
Sulfate ion	SO4 2-		chem-compound-formulas
Nitrate ion	NO3-		chem-compound-formulas
Carbonate ion	CO3 2-		chem-compound-formulas
Hydroxide ion	OH-		chem-compound-formulas
Phosphate ion	PO4 3-		chem-compound-formulas
Which element is the lightest and most common in the universe?	Hydrogen		chem-element-facts
Which gas makes up about 78% of Earth's air?	Nitrogen		chem-element-facts
Which gas do we breathe in to live, about 21% of the air?	Oxygen		chem-element-facts
Which element is the basis of all known life?	Carbon		chem-element-facts
Which two forms of pure carbon are very different: one soft and one super hard?	Graphite and diamond		chem-element-facts
Which noble gas is used to fill party balloons that float?	Helium		chem-element-facts
Which element is the only metal that is liquid at room temperature?	Mercury		chem-element-facts
Which element has the symbol Au and is a shiny yellow metal?	Gold		chem-element-facts
Which metal is used in most electrical wires?	Copper		chem-element-facts
Which metal is the main ingredient of steel?	Iron		chem-element-facts
Which element do bones and teeth need, found in milk?	Calcium		chem-element-facts
Which element is in table salt along with chlorine?	Sodium		chem-element-facts
Which gas is used to disinfect swimming pools?	Chlorine		chem-element-facts
Which noble gas glows red-orange in signs?	Neon		chem-element-facts
Which element is the most common metal in Earth's crust?	Aluminum		chem-element-facts
Which element is the second most common in Earth's crust, found in sand and glass?	Silicon		chem-element-facts
Which element is used in computer chips?	Silicon		chem-element-facts
Which metal is a good conductor and is used for jewelry and mirrors, symbol Ag?	Silver		chem-element-facts
Which element makes matches burn and is found in DNA?	Phosphorus		chem-element-facts
Which yellow solid smells like rotten eggs in some compounds?	Sulfur		chem-element-facts
Which element helps prevent tooth decay in toothpaste?	Fluorine, as fluoride		chem-element-facts
Which element is needed in the thyroid gland and is added to table salt?	Iodine		chem-element-facts
Which element is at the center of the Sun's fuel and fuses into helium?	Hydrogen		chem-element-facts
Which element is the second most abundant in the universe?	Helium		chem-element-facts
Which element is the hardest natural material (a form of carbon)?	Diamond, which is carbon		chem-element-facts
Which metal is used to coat steel to stop rust, as in galvanizing?	Zinc		chem-element-facts
Which heavy, soft metal is used in car batteries?	Lead		chem-element-facts
Which element has the highest atomic number that occurs naturally in large amounts in Earth's crust?	Uranium (92)		chem-element-facts
Which element is named after the Sun's Greek name Helios?	Helium		chem-element-facts
Which metal is attracted to magnets and is the core of Earth?	Iron		chem-element-facts
Which light metal is used for airplane parts and soda cans?	Aluminum		chem-element-facts
Which bright white metal burns with a dazzling flame and is in fireworks and flares?	Magnesium		chem-element-facts
Which metal is soft enough to cut with a knife and reacts violently with water?	Sodium		chem-element-facts
Which element is the N in fertilizer labels like N-P-K?	Nitrogen		chem-element-facts
Which metal is mixed with copper to make bronze?	Tin		chem-element-facts
Which element is a purple-black solid that turns into purple vapor when heated?	Iodine		chem-element-facts
Which noble gas is used in light bulbs to protect the filament?	Argon		chem-element-facts
Which element is named for Poland, the homeland of Marie Curie?	Polonium		chem-element-facts
Which element was named after Marie and Pierre Curie?	Curium		chem-element-facts
Which element is named after Albert Einstein?	Einsteinium		chem-element-facts
Which element is named after Dmitri Mendeleev?	Mendelevium		chem-element-facts
Which element is named after Niels Bohr?	Bohrium		chem-element-facts
Which element is named after planet Neptune?	Neptunium		chem-element-facts
Which element is named after planet Uranus?	Uranium		chem-element-facts
Which element is named after the Greek word for "green"?	Chlorine (from chloros)		chem-element-facts
Which element is named after the state of California?	Californium		chem-element-facts
Which element is named after Selene, the Greek moon goddess?	Selenium		chem-element-facts
Which element is used to make the strongest magnets, the neodymium kind?	Neodymium		chem-element-facts
Which element is the most electronegative?	Fluorine		chem-element-facts
Which element is a green poisonous gas used long ago and in swimming pools?	Chlorine		chem-element-facts
Which metal is the best conductor of electricity?	Silver		chem-element-facts
Which element makes up the largest part of the human body by mass?	Oxygen		chem-element-facts
What is the most abundant element in the human body by number of atoms?	Hydrogen		chem-element-facts
Which element is liquid at room temperature besides mercury, a reddish-brown liquid?	Bromine		chem-element-facts
Which element has the symbol Pt and is very valuable and does not tarnish?	Platinum		chem-element-facts
Which metal has the highest melting point of all metals?	Tungsten		chem-element-facts
Which element is used in the filaments of old light bulbs?	Tungsten		chem-element-facts
Which element is a radioactive gas found in some basements?	Radon		chem-element-facts
Which element is used in nuclear power plants as fuel?	Uranium		chem-element-facts
Which element is the first in the noble gas family?	Helium		chem-element-facts
Which element is a shiny gray solid that is a metalloid and used in solar panels?	Silicon		chem-element-facts
Which element makes the flame of some fireworks red?	Strontium		chem-element-facts
Which element makes the flame of some fireworks green?	Barium		chem-element-facts
Which element makes the flame of some fireworks blue?	Copper		chem-element-facts
Which element is in chlorophyll at the center of the molecule?	Magnesium		chem-element-facts
Which element is at the center of hemoglobin and helps carry oxygen in blood?	Iron		chem-element-facts
Hydrogen	H		chem-element-symbols
Helium	He		chem-element-symbols
Lithium	Li		chem-element-symbols
Beryllium	Be		chem-element-symbols
Boron	B		chem-element-symbols
Carbon	C		chem-element-symbols
Nitrogen	N		chem-element-symbols
Oxygen	O		chem-element-symbols
Fluorine	F		chem-element-symbols
Neon	Ne		chem-element-symbols
Sodium	Na (From the Latin natrium)		chem-element-symbols
Magnesium	Mg		chem-element-symbols
Aluminum	Al		chem-element-symbols
Silicon	Si		chem-element-symbols
Phosphorus	P		chem-element-symbols
Sulfur	S		chem-element-symbols
Chlorine	Cl		chem-element-symbols
Argon	Ar		chem-element-symbols
Potassium	K (From the Latin kalium)		chem-element-symbols
Calcium	Ca		chem-element-symbols
Scandium	Sc		chem-element-symbols
Titanium	Ti		chem-element-symbols
Vanadium	V		chem-element-symbols
Chromium	Cr		chem-element-symbols
Manganese	Mn		chem-element-symbols
Iron	Fe (From the Latin ferrum)		chem-element-symbols
Cobalt	Co		chem-element-symbols
Nickel	Ni		chem-element-symbols
Copper	Cu (From the Latin cuprum)		chem-element-symbols
Zinc	Zn		chem-element-symbols
Gallium	Ga		chem-element-symbols
Germanium	Ge		chem-element-symbols
Arsenic	As		chem-element-symbols
Selenium	Se		chem-element-symbols
Bromine	Br		chem-element-symbols
Krypton	Kr		chem-element-symbols
Rubidium	Rb		chem-element-symbols
Strontium	Sr		chem-element-symbols
Zirconium	Zr		chem-element-symbols
Molybdenum	Mo		chem-element-symbols
Silver	Ag (From the Latin argentum)		chem-element-symbols
Cadmium	Cd		chem-element-symbols
Tin	Sn (From the Latin stannum)		chem-element-symbols
Antimony	Sb (From the Latin stibium)		chem-element-symbols
Iodine	I		chem-element-symbols
Xenon	Xe		chem-element-symbols
Cesium	Cs		chem-element-symbols
Barium	Ba		chem-element-symbols
Tungsten	W (From the German wolfram)		chem-element-symbols
Platinum	Pt		chem-element-symbols
Gold	Au (From the Latin aurum)		chem-element-symbols
Mercury	Hg (From the Latin hydrargyrum)		chem-element-symbols
Lead	Pb (From the Latin plumbum)		chem-element-symbols
Bismuth	Bi		chem-element-symbols
Radon	Rn		chem-element-symbols
Radium	Ra		chem-element-symbols
Uranium	U		chem-element-symbols
Plutonium	Pu		chem-element-symbols
Neodymium	Nd		chem-element-symbols
Lanthanum	La		chem-element-symbols
Cerium	Ce		chem-element-symbols
Thorium	Th		chem-element-symbols
Iridium	Ir		chem-element-symbols
Osmium	Os		chem-element-symbols
Palladium	Pd		chem-element-symbols
Tellurium	Te		chem-element-symbols
Francium	Fr		chem-element-symbols
Astatine	At		chem-element-symbols
Beaker	Holds, mixes and heats liquids; rough measuring only		chem-lab-equipment
Erlenmeyer flask	Cone-shaped flask for mixing and swirling liquids		chem-lab-equipment
Florence flask	Round flask with a long neck for heating liquids		chem-lab-equipment
Graduated cylinder	Measures the volume of a liquid accurately		chem-lab-equipment
Test tube	Holds small amounts of material for tests		chem-lab-equipment
Test tube rack	Holds test tubes upright		chem-lab-equipment
Test tube holder	Grips a hot test tube		chem-lab-equipment
Test tube brush	Cleans the inside of test tubes		chem-lab-equipment
Bunsen burner	Gas burner used for heating		chem-lab-equipment
Hot plate	Electric surface for heating		chem-lab-equipment
Tongs	Pick up hot objects		chem-lab-equipment
Crucible tongs	Hold crucibles that are very hot		chem-lab-equipment
Crucible	Small cup for heating substances to very high temperatures		chem-lab-equipment
Ring stand	Metal stand that supports other lab equipment		chem-lab-equipment
Ring clamp	Attaches to a ring stand to hold a flask or funnel		chem-lab-equipment
Wire gauze	Spreads heat evenly under a beaker		chem-lab-equipment
Tripod	Three-legged stand to hold items over a flame		chem-lab-equipment
Funnel	Directs liquids into small openings		chem-lab-equipment
Filter paper	Traps solids when pouring a mixture through a funnel		chem-lab-equipment
Pipette	Moves small amounts of liquid, drop by drop		chem-lab-equipment
Dropper	Adds liquid in small drops		chem-lab-equipment
Buret	Long tube with a valve to deliver exact amounts of liquid		chem-lab-equipment
Volumetric flask	Makes solutions of an exact volume		chem-lab-equipment
Watch glass	Curved glass dish for holding or covering small samples		chem-lab-equipment
Petri dish	Shallow dish for growing cultures or holding samples		chem-lab-equipment
Evaporating dish	Used to evaporate liquid and leave the solid		chem-lab-equipment
Mortar and pestle	Grinds solids into powder		chem-lab-equipment
Spatula	Scoops and transfers solid chemicals		chem-lab-equipment
Stirring rod	Glass rod used to mix liquids		chem-lab-equipment
Forceps	Small tweezers for picking up tiny items		chem-lab-equipment
Balance (scale)	Measures mass		chem-lab-equipment
Triple beam balance	Measures mass by sliding weights on three beams		chem-lab-equipment
Thermometer	Measures temperature		chem-lab-equipment
Stopwatch	Measures time		chem-lab-equipment
Microscope	Magnifies tiny objects		chem-lab-equipment
Slide	Thin glass that holds a sample under a microscope		chem-lab-equipment
Cover slip	Thin square of glass or plastic placed over a sample on a slide		chem-lab-equipment
Magnifying glass	A lens that makes small things look larger		chem-lab-equipment
Meter stick	Measures length in centimeters and millimeters		chem-lab-equipment
Ruler	Measures short lengths		chem-lab-equipment
Safety goggles	Protect the eyes		chem-lab-equipment
pH paper	Paper that changes color to show if something is an acid or base		chem-lab-equipment
Litmus paper	Paper that turns red in acid and blue in base		chem-lab-equipment
Wash bottle	Squeeze bottle that holds water for rinsing		chem-lab-equipment
Dissecting pan	Tray used to hold specimens for dissection		chem-lab-equipment
Scalpel	Small sharp blade for dissection, used only by trained users		chem-lab-equipment
Dissecting probe	Pointer used to move parts of a specimen		chem-lab-equipment
Centrifuge	Spins samples quickly to separate parts by density		chem-lab-equipment
Desiccator	Sealed container that keeps things dry		chem-lab-equipment
Fume hood	Ventilated enclosure that removes harmful fumes		chem-lab-equipment
Spring scale	Measures force or weight		chem-lab-equipment
Barometer	Measures air pressure		chem-lab-equipment
Hydrometer	Measures the density of a liquid		chem-lab-equipment
Calorimeter	Measures heat given off or taken in by a reaction		chem-lab-equipment
Spectroscope	Splits light into a spectrum		chem-lab-equipment
Telescope	Makes distant objects like stars look closer		chem-lab-equipment
Compass	Shows direction by pointing toward magnetic north		chem-lab-equipment
Anemometer	Measures wind speed		chem-lab-equipment
Rain gauge	Measures how much rain falls		chem-lab-equipment
Before starting a lab	Read the directions and listen to your teacher		chem-lab-safety
Goggles	Wear them to protect your eyes whenever told to		chem-lab-safety
Long hair	Tie it back so it stays away from flames and chemicals		chem-lab-safety
Loose sleeves and jewelry	Roll up or remove them so they don't catch		chem-lab-safety
Shoes in lab	Wear closed-toe shoes, never sandals		chem-lab-safety
Lab apron or coat	Wear it to protect skin and clothes		chem-lab-safety
Gloves	Wear them when handling chemicals your teacher says need them		chem-lab-safety
Eating and drinking in the lab	Never do it		chem-lab-safety
Tasting chemicals	Never taste anything in the lab		chem-lab-safety
Smelling a chemical	Waft the fumes toward your nose with your hand; don't sniff directly		chem-lab-safety
Running in the lab	Don't; walk calmly		chem-lab-safety
Spill	Tell your teacher right away		chem-lab-safety
Broken glass	Tell your teacher; don't pick it up with bare hands		chem-lab-safety
Hot object	Use tongs or heat-proof gloves and treat it as hot		chem-lab-safety
Heating a test tube	Point the opening away from yourself and others		chem-lab-safety
Bunsen burner	Keep flammable things away and never leave it unattended		chem-lab-safety
Lighting a burner	Light the match first, then turn on the gas, with teacher watching		chem-lab-safety
Adding acid to water	Always add acid slowly to water, never water to acid		chem-lab-safety
Mixing unknown chemicals	Never do it		chem-lab-safety
Labels	Read the label twice before using a chemical		chem-lab-safety
Unused chemicals	Never pour them back in the original bottle		chem-lab-safety
Waste	Dispose of it the way your teacher says		chem-lab-safety
After the lab	Wash your hands with soap and water		chem-lab-safety
Eyewash station	Use it right away to flush chemicals from the eyes		chem-lab-safety
Safety shower	Used to rinse chemicals off the body in an emergency		chem-lab-safety
Fire extinguisher	Used to put out small fires, after telling the teacher		chem-lab-safety
Fire blanket	Wraps around a person to smother flames		chem-lab-safety
Clothes on fire	Stop, drop and roll		chem-lab-safety
Fume hood	A ventilated cabinet that pulls harmful fumes away		chem-lab-safety
Hazard symbol with a flame	Flammable: can catch fire		chem-lab-safety
Hazard symbol with a skull and crossbones	Toxic: can poison		chem-lab-safety
Hazard symbol with an exclamation mark	Irritant or other less severe health hazard		chem-lab-safety
Hazard symbol with a corroded hand	Corrosive: can damage skin and metal		chem-lab-safety
Hazard symbol with an exploding bomb	Explosive or reactive		chem-lab-safety
Hazard symbol with a dead tree and fish	Harmful to the environment		chem-lab-safety
SDS	Safety Data Sheet: tells how to handle a chemical safely		chem-lab-safety
Using electrical equipment	Keep cords and hands dry and away from water		chem-lab-safety
Working alone in the lab	Don't; always have an adult present		chem-lab-safety
Horseplay	Never; it causes accidents		chem-lab-safety
Pouring from a bottle	Hold the label side up against your palm		chem-lab-safety
Cleaning up	Leave your work area clean and tidy		chem-lab-safety
Cuts or burns	Tell the teacher at once		chem-lab-safety
Glassware that is cracked	Do not use it; give it to the teacher		chem-lab-safety
Carrying a microscope	Use two hands, one on the arm and one under the base		chem-lab-safety
Testing something that might be hot	Hold your hand near, not on it		chem-lab-safety
Group	A column of the periodic table; elements in it act alike		chem-periodic-table-groups
Period	A row of the periodic table		chem-periodic-table-groups
How many groups are in the standard periodic table?	18		chem-periodic-table-groups
How many periods are in the standard periodic table?	7		chem-periodic-table-groups
Alkali metals	Group 1 (except hydrogen): very reactive soft metals like sodium		chem-periodic-table-groups
Alkaline earth metals	Group 2: reactive metals like calcium and magnesium		chem-periodic-table-groups
Transition metals	The block in the middle, like iron, copper and gold		chem-periodic-table-groups
Halogens	Group 17: reactive nonmetals like chlorine and iodine		chem-periodic-table-groups
Noble gases	Group 18: very unreactive gases like helium and neon		chem-periodic-table-groups
Metalloids	Elements with properties of both metals and nonmetals, like silicon		chem-periodic-table-groups
Nonmetals	Elements that are usually dull, brittle and poor conductors		chem-periodic-table-groups
Metals	Shiny elements that conduct heat and electricity and can be shaped		chem-periodic-table-groups
Lanthanides	Row of 15 elements shown below the main table, from lanthanum		chem-periodic-table-groups
Actinides	Row of 15 elements shown below the main table, from actinium		chem-periodic-table-groups
Atomic number	The number of protons in an atom's nucleus		chem-periodic-table-groups
Atomic mass	The average mass of an element's atoms, in atomic mass units		chem-periodic-table-groups
Element symbol	One or two letters standing for an element; the first is capital		chem-periodic-table-groups
Who created the first widely used periodic table in 1869?	Dmitri Mendeleev		chem-periodic-table-groups
How did Mendeleev arrange the elements?	By atomic mass, leaving gaps for undiscovered elements		chem-periodic-table-groups
How is the modern table arranged?	By increasing atomic number		chem-periodic-table-groups
Valence electrons	Electrons in an atom's outermost shell		chem-periodic-table-groups
How many valence electrons do halogens have?	7		chem-periodic-table-groups
How many valence electrons do alkali metals have?	1		chem-periodic-table-groups
How many valence electrons do most noble gases have?	8 (helium has 2)		chem-periodic-table-groups
Which group contains carbon?	Group 14		chem-periodic-table-groups
Which group contains oxygen?	Group 16		chem-periodic-table-groups
Which group contains nitrogen?	Group 15		chem-periodic-table-groups
Which element is placed alone at the top-left, and is not an alkali metal?	Hydrogen		chem-periodic-table-groups
Which side of the table holds mostly metals?	The left side and middle		chem-periodic-table-groups
Which side of the table holds the nonmetals?	The upper right		chem-periodic-table-groups
What is the zigzag line on the right side of the table for?	It separates metals from nonmetals; metalloids sit along it		chem-periodic-table-groups
Why are noble gases unreactive?	Their outer electron shell is full		chem-periodic-table-groups
Why do elements in a group act alike?	They have the same number of valence electrons		chem-periodic-table-groups
Which period 1 elements exist?	Hydrogen and helium		chem-periodic-table-groups
Which is the lightest metal, atomic number 3?	Lithium		chem-periodic-table-groups
Synthetic element	One made in a lab and not found in nature in large amounts		chem-periodic-table-groups
Radioactive element	An element whose atoms break down and give off energy		chem-periodic-table-groups
Which element has the lowest atomic number?	Hydrogen (1)		chem-periodic-table-groups
Isotope	Atoms of the same element with different numbers of neutrons		chem-periodic-table-groups
Matter	Anything that has mass and takes up space		chem-states-of-matter
Solid	Matter with a fixed shape and fixed volume		chem-states-of-matter
Liquid	Matter with a fixed volume that takes the shape of its container		chem-states-of-matter
Gas	Matter with no fixed shape or volume; it spreads out to fill space		chem-states-of-matter
Plasma	A hot, glowing state of matter made of charged particles		chem-states-of-matter
Where is plasma found?	In stars, lightning and neon signs		chem-states-of-matter
Bose-Einstein condensate	A state of matter formed near absolute zero where atoms act as one		chem-states-of-matter
Particles in a solid	Packed close and only vibrate in place		chem-states-of-matter
Particles in a liquid	Close together but able to slide past each other		chem-states-of-matter
Particles in a gas	Far apart and moving fast in all directions		chem-states-of-matter
Melting	Solid turns to liquid		chem-states-of-matter
Freezing	Liquid turns to solid		chem-states-of-matter
Evaporation	Liquid turns to gas at the surface		chem-states-of-matter
Boiling	Liquid turns to gas throughout, with bubbles		chem-states-of-matter
Condensation	Gas turns to liquid		chem-states-of-matter
Sublimation	Solid turns straight into gas		chem-states-of-matter
Deposition	Gas turns straight into solid		chem-states-of-matter
Melting point of water	0 degrees Celsius (32 degrees Fahrenheit)		chem-states-of-matter
Boiling point of water	100 degrees Celsius (212 degrees Fahrenheit) at sea level		chem-states-of-matter
Example of sublimation	Dry ice (solid carbon dioxide) turning into gas		chem-states-of-matter
Example of deposition	Frost forming on a cold window		chem-states-of-matter
Is steam a gas or liquid droplets?	Invisible steam is a gas; the white cloud you see is tiny liquid drops		chem-states-of-matter
Does heating add or remove energy?	It adds energy, making particles move faster		chem-states-of-matter
What happens to particles when matter cools?	They slow down		chem-states-of-matter
Which state is the easiest to squeeze?	Gas		chem-states-of-matter
Which state is almost impossible to squeeze?	Solid and liquid		chem-states-of-matter
Does a liquid have a definite volume?	Yes		chem-states-of-matter
Does a gas have a definite volume?	No		chem-states-of-matter
Is ice a solid, liquid or gas?	Solid		chem-states-of-matter
Is water vapor a solid, liquid or gas?	Gas		chem-states-of-matter
Is air a solid, liquid or gas?	A mixture of gases		chem-states-of-matter
Is honey a solid or liquid?	Liquid		chem-states-of-matter
Is sand a solid?	Yes; each grain is a tiny solid		chem-states-of-matter
Which is denser, ice or liquid water?	Liquid water; ice floats		chem-states-of-matter
Why does ice float?	Water expands as it freezes, so ice is less dense		chem-states-of-matter
Viscosity	How much a liquid resists flowing		chem-states-of-matter
Surface tension	The pull between liquid molecules that makes a skin at the surface		chem-states-of-matter
Compressibility	How much a material can be squeezed into less space		chem-states-of-matter
Vapor	The gas form of a substance that is usually a liquid or solid		chem-states-of-matter
Freezing point	The temperature at which a liquid becomes a solid		chem-states-of-matter
Latent heat	Energy absorbed or released during a change of state without changing temperature		chem-states-of-matter
Phase diagram	A graph showing the state of a substance at different temperatures and pressures		chem-states-of-matter
Absolute zero	The lowest possible temperature, -273.15 degrees Celsius		chem-states-of-matter
Pressure	Force pushing on a surface		chem-states-of-matter
Kinetic theory of matter	All matter is made of tiny particles in constant motion		chem-states-of-matter
Diffusion	Particles spreading from where there are many to where there are few		chem-states-of-matter
Which state of matter makes up most of the visible universe?	Plasma		chem-states-of-matter
Dry ice is made of what?	Frozen carbon dioxide		chem-states-of-matter
Is a cloud made of gas?	It is made of tiny liquid droplets or ice crystals in air		chem-states-of-matter
Is toothpaste a solid or liquid?	It acts like both, a gel-like material		chem-states-of-matter
Tyrannosaurus rex	A huge meat-eating dinosaur with a powerful bite and tiny arms		dinosaurs
Triceratops	A plant eater with three horns and a bony frill		dinosaurs
Stegosaurus	A plant eater with back plates and a spiked tail		dinosaurs
Velociraptor	A small feathered meat eater about the size of a turkey		dinosaurs
Brachiosaurus	A tall, long-necked plant eater		dinosaurs
Diplodocus	A very long plant eater with a whip-like tail		dinosaurs
Apatosaurus	A huge long-necked plant eater, once called Brontosaurus		dinosaurs
Ankylosaurus	An armored plant eater with a club tail		dinosaurs
Spinosaurus	A large meat eater with a sail on its back that lived near water		dinosaurs
Allosaurus	A large meat eater from the Jurassic		dinosaurs
Giganotosaurus	A giant meat eater from South America		dinosaurs
Parasaurolophus	A duck-billed dinosaur with a long hollow crest		dinosaurs
Iguanodon	A plant eater with thumb spikes		dinosaurs
Pachycephalosaurus	A dinosaur with a thick domed skull		dinosaurs
Compsognathus	A tiny chicken-sized meat eater		dinosaurs
Argentinosaurus	One of the largest known land animals, a titanosaur		dinosaurs
Archaeopteryx	An early feathered animal linking dinosaurs and birds		dinosaurs
Microraptor	A small four-winged feathered dinosaur		dinosaurs
Oviraptor	A feathered dinosaur whose name means egg thief, though it was probably a good parent		dinosaurs
Maiasaura	A duck-billed dinosaur whose name means good mother lizard		dinosaurs
Gallimimus	A fast, ostrich-like dinosaur		dinosaurs
Utahraptor	A big raptor from Utah		dinosaurs
Dilophosaurus	An early meat eater with two crests		dinosaurs
Carnotaurus	A meat eater with horns over its eyes		dinosaurs
Protoceratops	A small horned dinosaur that lived in Mongolia		dinosaurs
Pteranodon	A flying reptile (pterosaur) that was not a dinosaur		dinosaurs
Quetzalcoatlus	A giant pterosaur with a huge wingspan		dinosaurs
Mosasaurus	A giant sea reptile, not a dinosaur		dinosaurs
Plesiosaur	A long-necked sea reptile, not a dinosaur		dinosaurs
Ichthyosaur	A dolphin-shaped sea reptile		dinosaurs
Dimetrodon	A sail-backed animal older than dinosaurs, not a dinosaur		dinosaurs
Woolly mammoth	An ice age elephant relative with long tusks		dinosaurs
Saber-toothed cat	An ice age cat with long upper teeth		dinosaurs
Megalodon	A huge extinct shark		dinosaurs
Trilobite	An ancient sea arthropod found as fossils		dinosaurs
Mesozoic Era	The age of dinosaurs, about 252 to 66 million years ago		dinosaurs
Triassic Period	First part of the Mesozoic; the first dinosaurs appear		dinosaurs
Jurassic Period	Middle part of the Mesozoic; long-necked giants and early birds		dinosaurs
Cretaceous Period	Last part of the Mesozoic; T. rex and Triceratops lived		dinosaurs
How long ago did non-bird dinosaurs die out?	About 66 million years ago		dinosaurs
What likely caused the dinosaur extinction?	A giant asteroid hit Earth		dinosaurs
Where did the asteroid land?	Near the Yucatan Peninsula in Mexico (Chicxulub)		dinosaurs
Do dinosaurs still live today?	Yes, as birds		dinosaurs
Fossil	The preserved remains or traces of ancient life		dinosaurs
Paleontologist	A scientist who studies fossils		dinosaurs
Trace fossil	Evidence like footprints or burrows		dinosaurs
Coprolite	Fossilized dung		dinosaurs
Amber	Fossilized tree resin that can trap insects		dinosaurs
Mold fossil	An imprint left in rock		dinosaurs
Petrified wood	Wood turned to stone by minerals		dinosaurs
Herbivore	Plant eater		dinosaurs
Carnivore	Meat eater		dinosaurs
Omnivore	Eats both plants and meat		dinosaurs
Sauropod	A giant long-necked, four-legged plant eater		dinosaurs
Theropod	A two-legged mostly meat-eating dinosaur		dinosaurs
Ornithopod	A plant-eating dinosaur like duck-billed hadrosaurs		dinosaurs
Ceratopsian	A horned, frilled dinosaur like Triceratops		dinosaurs
Dinosaur means	Terrible lizard		dinosaurs
Who coined the word dinosaur in 1842?	Richard Owen		dinosaurs
Mary Anning	A fossil collector who found early marine reptile skeletons in England		dinosaurs
Dinosaur National Monument	A park in Utah and Colorado with fossil bones		dinosaurs
Sue	A famous T. rex skeleton at the Field Museum in Chicago		dinosaurs
Longest dinosaurs	Some sauropods grew over 30 meters long		dinosaurs
Egg-laying	Dinosaurs laid eggs in nests		dinosaurs
Feathers	Many dinosaurs, especially raptors, had feathers		dinosaurs
Pangaea	The supercontinent where early dinosaurs lived		dinosaurs
Cirrus	High, thin, wispy clouds made of ice crystals		earth-clouds
Cirrostratus	High, thin sheet that can make a halo around the Sun		earth-clouds
Cirrocumulus	High, small rippled clouds in rows		earth-clouds
Altostratus	Middle-level gray or blue-gray sheet that can cover the sky		earth-clouds
Altocumulus	Middle-level puffy patches in rows		earth-clouds
Stratus	Low gray layer like fog above the ground		earth-clouds
Stratocumulus	Low, lumpy gray and white clouds		earth-clouds
Nimbostratus	Thick, dark layer that brings steady rain or snow		earth-clouds
Cumulus	Fluffy white clouds with flat bottoms		earth-clouds
Cumulonimbus	Tall thunderstorm clouds		earth-clouds
Which cloud makes thunderstorms?	Cumulonimbus		earth-clouds
Which cloud usually means fair weather?	Cumulus		earth-clouds
Which clouds are the highest?	Cirrus family		earth-clouds
Which clouds are low-level?	Stratus, stratocumulus and nimbostratus		earth-clouds
What does cirro- mean?	High, wispy or curly		earth-clouds
What does stratus mean?	Layer or sheet		earth-clouds
What does cumulus mean?	Heap or pile		earth-clouds
What does nimbus mean?	Rain-bearing		earth-clouds
What does alto- mean?	Middle level		earth-clouds
Contrail	A cloud-like trail left behind by a high-flying airplane		earth-clouds
Fog	A cloud that touches the ground		earth-clouds
Mist	A thin fog with tiny water droplets		earth-clouds
Lenticular cloud	A smooth, lens-shaped cloud often near mountains		earth-clouds
Mammatus cloud	Pouch-like bulges on the underside of a cloud		earth-clouds
Noctilucent cloud	Very high thin cloud that glows at twilight		earth-clouds
Anvil cloud	The flat top of a cumulonimbus		earth-clouds
Funnel cloud	A rotating cone of cloud that hasn't touched the ground		earth-clouds
Shelf cloud	Low wedge-shaped cloud at the front of a storm		earth-clouds
Wall cloud	A lowered cloud base under a storm that can produce tornadoes		earth-clouds
How do clouds form?	Rising air cools and water vapor condenses on tiny particles		earth-clouds
What are clouds made of?	Tiny water droplets or ice crystals		earth-clouds
Why do clouds float?	The droplets are so tiny that rising air keeps them up		earth-clouds
Condensation nuclei	Tiny bits of dust or salt that droplets form on		earth-clouds
Cloud cover	How much of the sky is covered by clouds		earth-clouds
Overcast	A sky fully covered by clouds		earth-clouds
Partly cloudy	A sky with some clouds and some blue		earth-clouds
Why are clouds white?	They scatter all colors of sunlight		earth-clouds
Why are storm clouds dark?	They are so thick that little light passes through		earth-clouds
Cumulus humilis	Small, flat fair-weather cumulus		earth-clouds
Cumulus congestus	Tall towering cumulus that can grow into storms		earth-clouds
Mackerel sky	Cirrocumulus or altocumulus that looks like fish scales		earth-clouds
Mares' tails	Long streaks of cirrus clouds		earth-clouds
Halo	A ring of light around the Sun or Moon from ice crystals in thin clouds		earth-clouds
Virga	Rain that evaporates before reaching the ground		earth-clouds
Altitude of high clouds	Above about 6 kilometers		earth-clouds
Altitude of low clouds	Below about 2 kilometers		earth-clouds
Crust	Earth's thin, rocky outer layer		earth-layers-landforms
Mantle	The thick layer of hot rock beneath the crust		earth-layers-landforms
Outer core	A layer of liquid iron and nickel		earth-layers-landforms
Inner core	A solid ball of iron and nickel at Earth's center		earth-layers-landforms
Which Earth layer is thickest?	The mantle		earth-layers-landforms
Which Earth layer is thinnest?	The crust		earth-layers-landforms
Continental crust	The thicker crust that makes up the continents		earth-layers-landforms
Oceanic crust	The thinner, denser crust under the oceans		earth-layers-landforms
Moho	The boundary between the crust and mantle		earth-layers-landforms
Troposphere	The lowest layer of the atmosphere, where weather happens		earth-layers-landforms
Stratosphere	The atmosphere layer above the troposphere, holding the ozone layer		earth-layers-landforms
Mesosphere	The layer where most meteors burn up		earth-layers-landforms
Thermosphere	The layer where auroras happen and the space station orbits		earth-layers-landforms
Exosphere	The outermost atmosphere layer fading into space		earth-layers-landforms
Ozone layer	A layer that absorbs harmful ultraviolet light		earth-layers-landforms
Hydrosphere	All the water on Earth		earth-layers-landforms
Lithosphere	Earth's rigid outer shell		earth-layers-landforms
Biosphere	All living things on Earth		earth-layers-landforms
Atmosphere	The blanket of gases around Earth		earth-layers-landforms
Percent of Earth covered by water, about	71 percent		earth-layers-landforms
Percent of Earth's water that is salty, about	97 percent		earth-layers-landforms
Mountain	A very high landform with steep sides		earth-layers-landforms
Hill	A raised landform lower than a mountain		earth-layers-landforms
Valley	Low land between hills or mountains		earth-layers-landforms
Canyon	A deep valley with steep sides, often cut by a river		earth-layers-landforms
Plateau	A high, flat landform		earth-layers-landforms
Plain	A large flat area of land		earth-layers-landforms
Mesa	A flat-topped hill with steep sides		earth-layers-landforms
Butte	A small, steep-sided hill with a flat top		earth-layers-landforms
Peninsula	Land surrounded by water on three sides		earth-layers-landforms
Island	Land completely surrounded by water		earth-layers-landforms
Isthmus	A narrow strip of land connecting two larger landmasses		earth-layers-landforms
Archipelago	A group of islands		earth-layers-landforms
Delta	Land built up where a river empties into a larger body of water		earth-layers-landforms
Cape	A point of land that sticks out into water		earth-layers-landforms
Bay	Part of the sea that curves into the land		earth-layers-landforms
Gulf	A large bay		earth-layers-landforms
Strait	A narrow waterway between two larger bodies of water		earth-layers-landforms
Lake	A body of water surrounded by land		earth-layers-landforms
River	A large stream flowing to a lake or sea		earth-layers-landforms
Tributary	A stream that flows into a larger river		earth-layers-landforms
Source of a river	Where a river begins		earth-layers-landforms
Mouth of a river	Where a river ends		earth-layers-landforms
Watershed	The area of land that drains into a river		earth-layers-landforms
Dune	A hill of sand made by wind		earth-layers-landforms
Cave	A natural hollow in rock or ground		earth-layers-landforms
Cliff	A steep rock face		earth-layers-landforms
Glacier	A large, slow-moving river of ice		earth-layers-landforms
Iceberg	A large floating piece of ice broken from a glacier		earth-layers-landforms
Oasis	A fertile spot in the desert with water		earth-layers-landforms
Reef	A ridge of coral or rock near the surface of the sea		earth-layers-landforms
Atoll	A ring-shaped coral island		earth-layers-landforms
Fjord	A long, narrow sea inlet between steep cliffs		earth-layers-landforms
Tundra	A cold treeless plain		earth-layers-landforms
Prairie	A large grassy plain		earth-layers-landforms
Basin	A low area where water collects		earth-layers-landforms
Elevation	Height above sea level		earth-layers-landforms
Topographic map	A map showing the shape and height of land with contour lines		earth-layers-landforms
Contour line	A line on a map connecting points of equal elevation		earth-layers-landforms
Longitude	Distance east or west of the Prime Meridian		earth-layers-landforms
Latitude	Distance north or south of the Equator		earth-layers-landforms
Equator	The imaginary line at 0 degrees latitude around Earth's middle		earth-layers-landforms
Axis	The imaginary line Earth spins around		earth-layers-landforms
Rotation	Earth spinning, one turn each day		earth-layers-landforms
Revolution	Earth traveling around the Sun, one trip each year		earth-layers-landforms
Earth's axial tilt	About 23.5 degrees		earth-layers-landforms
Cause of the seasons	Earth's tilted axis as it orbits the Sun		earth-layers-landforms
Solstice	The day with the most or least daylight in a year		earth-layers-landforms
Equinox	A day when day and night are nearly equal		earth-layers-landforms
Mineral	A natural, solid, nonliving substance with a crystal structure and set chemical makeup		earth-minerals
Luster	How the surface of a mineral reflects light		earth-minerals
Streak	The color of a mineral's powder when rubbed on a plate		earth-minerals
Hardness	How easily a mineral can be scratched		earth-minerals
Mohs scale	A scale of mineral hardness from 1 to 10		earth-minerals
Cleavage	When a mineral breaks along flat surfaces		earth-minerals
Fracture	When a mineral breaks unevenly		earth-minerals
Crystal form	The shape of a mineral's crystals		earth-minerals
Specific gravity	How heavy a mineral is compared to water		earth-minerals
Magnetism	Some minerals, like magnetite, are attracted to a magnet		earth-minerals
Ore	A rock that has enough metal to be worth mining		earth-minerals
Gemstone	A mineral cut and polished for jewelry		earth-minerals
Mohs hardness 1	Talc		earth-minerals
Mohs hardness 2	Gypsum		earth-minerals
Mohs hardness 3	Calcite		earth-minerals
Mohs hardness 4	Fluorite		earth-minerals
Mohs hardness 5	Apatite		earth-minerals
Mohs hardness 6	Orthoclase feldspar		earth-minerals
Mohs hardness 7	Quartz		earth-minerals
Mohs hardness 8	Topaz		earth-minerals
Mohs hardness 9	Corundum		earth-minerals
Mohs hardness 10	Diamond		earth-minerals
Memory trick for the Mohs scale	Talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz, corundum, diamond		earth-minerals
Softest mineral	Talc		earth-minerals
Hardest natural mineral	Diamond		earth-minerals
Talc	Very soft mineral used to make baby powder		earth-minerals
Gypsum	Soft mineral used for plaster and drywall		earth-minerals
Calcite	Mineral that fizzes in vinegar; makes up limestone		earth-minerals
Quartz	Common hard mineral in sand and granite		earth-minerals
Feldspar	The most common mineral group in Earth's crust		earth-minerals
Mica	Mineral that splits into thin shiny sheets		earth-minerals
Halite	The mineral name for rock salt		earth-minerals
Pyrite	Brassy mineral called fool's gold		earth-minerals
Galena	The main ore of lead		earth-minerals
Hematite	An iron ore with a reddish-brown streak		earth-minerals
Magnetite	A magnetic iron ore		earth-minerals
Bauxite	The main ore of aluminum		earth-minerals
Graphite	Soft carbon mineral used in pencils		earth-minerals
Diamond	Carbon mineral, the hardest natural substance		earth-minerals
Corundum	Mineral that makes rubies and sapphires		earth-minerals
Ruby	A red gem form of corundum		earth-minerals
Sapphire	Usually blue gem form of corundum		earth-minerals
Emerald	A green gem form of beryl		earth-minerals
Amethyst	Purple quartz		earth-minerals
Topaz	A hard gem mineral that comes in many colors		earth-minerals
Garnet	A group of minerals, often deep red		earth-minerals
Opal	A gem with flashing colors, made of silica and water		earth-minerals
Turquoise	A blue-green mineral used in jewelry		earth-minerals
Jade	A green stone used for carvings		earth-minerals
Malachite	A bright green copper mineral		earth-minerals
Fluorite	A mineral that can glow under UV light and comes in many colors		earth-minerals
Sulfur	A yellow mineral element		earth-minerals
Gold	A soft, heavy, valuable native metal		earth-minerals
Native element	A mineral made of just one element, like gold or copper		earth-minerals
Geode	A rock with a hollow filled with crystals		earth-minerals
Stalactite	A mineral formation that hangs from a cave ceiling		earth-minerals
Stalagmite	A mineral formation that rises from a cave floor		earth-minerals
Mineral that your teeth and bones are like	Apatite		earth-minerals
Birthstone for April	Diamond		earth-minerals
Birthstone for January	Garnet		earth-minerals
Birthstone for September	Sapphire		earth-minerals
Plate tectonics	The theory that Earth's outer layer is broken into moving plates		earth-plate-tectonics
Tectonic plate	A large slab of Earth's lithosphere		earth-plate-tectonics
Lithosphere	Earth's rigid outer layer: crust and top of the mantle		earth-plate-tectonics
Asthenosphere	The soft, slowly flowing layer of mantle below the lithosphere		earth-plate-tectonics
Continental drift	The idea that continents slowly move over time		earth-plate-tectonics
Who proposed continental drift in 1912?	Alfred Wegener		earth-plate-tectonics
Pangaea	The supercontinent that existed about 300 million years ago		earth-plate-tectonics
Seafloor spreading	New ocean floor forming at mid-ocean ridges and moving outward		earth-plate-tectonics
Mid-ocean ridge	An underwater mountain chain where new crust forms		earth-plate-tectonics
Convergent boundary	Two plates moving toward each other		earth-plate-tectonics
Divergent boundary	Two plates moving apart		earth-plate-tectonics
Transform boundary	Two plates sliding past each other		earth-plate-tectonics
Subduction	One plate sinking beneath another		earth-plate-tectonics
Subduction zone	The place where one plate dives under another		earth-plate-tectonics
Ocean trench	A deep, narrow valley in the seafloor at a subduction zone		earth-plate-tectonics
Mariana Trench	The deepest known ocean trench		earth-plate-tectonics
Rift valley	A valley formed where plates pull apart		earth-plate-tectonics
Fault	A crack in Earth's crust where blocks of rock move		earth-plate-tectonics
San Andreas Fault	A famous transform fault in California		earth-plate-tectonics
Earthquake	Shaking of the ground from sudden release of energy in Earth's crust		earth-plate-tectonics
Focus (hypocenter)	The point underground where an earthquake starts		earth-plate-tectonics
Epicenter	The point on the surface directly above the focus		earth-plate-tectonics
Seismic waves	Vibrations that travel through Earth during an earthquake		earth-plate-tectonics
P waves	Fast seismic waves that arrive first		earth-plate-tectonics
S waves	Slower seismic waves that arrive second		earth-plate-tectonics
Surface waves	Seismic waves that move along the ground and cause the most damage		earth-plate-tectonics
Seismograph	An instrument that records earthquake waves		earth-plate-tectonics
Seismologist	A scientist who studies earthquakes		earth-plate-tectonics
Richter scale	An older scale of earthquake size		earth-plate-tectonics
Moment magnitude scale	The scale scientists now use to measure earthquake size		earth-plate-tectonics
Aftershock	A smaller quake that follows a larger one		earth-plate-tectonics
Tsunami	A giant sea wave usually caused by an undersea earthquake		earth-plate-tectonics
Ring of Fire	A belt of volcanoes and earthquakes around the Pacific Ocean		earth-plate-tectonics
Volcano	An opening in Earth's crust where lava, ash and gas escape		earth-plate-tectonics
Vent	An opening where magma comes out of a volcano		earth-plate-tectonics
Crater	A bowl-shaped dip at the top of a volcano		earth-plate-tectonics
Caldera	A large crater formed when a volcano collapses		earth-plate-tectonics
Magma chamber	An underground pool of magma		earth-plate-tectonics
Shield volcano	A wide, gently sloping volcano like those in Hawaii		earth-plate-tectonics
Composite (stratovolcano)	A steep cone built from layers of lava and ash		earth-plate-tectonics
Cinder cone	A small, steep cone of volcanic fragments		earth-plate-tectonics
Active volcano	One that is erupting or may erupt		earth-plate-tectonics
Dormant volcano	A volcano that is quiet but may erupt again		earth-plate-tectonics
Extinct volcano	A volcano that is not expected to erupt again		earth-plate-tectonics
Hot spot	A place deep in the mantle that feeds volcanoes, like Hawaii		earth-plate-tectonics
Pyroclastic flow	A fast cloud of hot gas and ash from a volcano		earth-plate-tectonics
Ash	Tiny rock and glass pieces thrown out by a volcano		earth-plate-tectonics
Mount St. Helens	A volcano in Washington State that erupted in 1980		earth-plate-tectonics
Mauna Loa	A huge shield volcano in Hawaii		earth-plate-tectonics
Mount Vesuvius	The volcano that buried Pompeii in the year 79		earth-plate-tectonics
Geyser	A hot spring that shoots water into the air		earth-plate-tectonics
Old Faithful	A famous geyser in Yellowstone National Park		earth-plate-tectonics
Fold mountains	Mountains formed when plates push together and crumple rock		earth-plate-tectonics
Himalayas	Mountains formed where India's plate pushes into Asia's		earth-plate-tectonics
Convection currents	Slow movements of hot mantle rock that help move the plates		earth-plate-tectonics
Evidence for drift: fossils	The same fossils appear on continents now far apart		earth-plate-tectonics
Evidence for drift: coastlines	South America and Africa fit together like puzzle pieces		earth-plate-tectonics
How fast do plates move?	A few centimeters a year, about as fast as fingernails grow		earth-plate-tectonics
Strike-slip fault	A fault where blocks slide sideways past each other		earth-plate-tectonics
Rock	A solid natural material made of one or more minerals		earth-rocks
Igneous rock	Rock formed when melted rock cools and hardens		earth-rocks
Sedimentary rock	Rock formed when sediments are pressed and cemented together		earth-rocks
Metamorphic rock	Rock changed by heat and pressure		earth-rocks
Magma	Melted rock beneath the surface		earth-rocks
Lava	Melted rock that has reached the surface		earth-rocks
Intrusive igneous rock	Igneous rock that cooled slowly underground, with large crystals		earth-rocks
Extrusive igneous rock	Igneous rock that cooled quickly at the surface, with small crystals		earth-rocks
Granite	A light-colored intrusive igneous rock with visible crystals		earth-rocks
Basalt	A dark, fine-grained extrusive igneous rock		earth-rocks
Obsidian	Natural volcanic glass		earth-rocks
Pumice	A light igneous rock full of holes that can float		earth-rocks
Rhyolite	An extrusive rock with the same makeup as granite		earth-rocks
Gabbro	A dark intrusive igneous rock		earth-rocks
Sandstone	Sedimentary rock made of cemented sand grains		earth-rocks
Limestone	Sedimentary rock made mostly of calcium carbonate		earth-rocks
Shale	Sedimentary rock made of compacted clay and mud		earth-rocks
Conglomerate	Sedimentary rock with rounded pebbles cemented in it		earth-rocks
Breccia	Sedimentary rock with angular fragments cemented together		earth-rocks
Coal	A sedimentary rock made from ancient plants		earth-rocks
Chalk	A soft, white form of limestone		earth-rocks
Marble	Metamorphic rock formed from limestone		earth-rocks
Slate	Metamorphic rock formed from shale; splits into flat sheets		earth-rocks
Quartzite	Metamorphic rock formed from sandstone		earth-rocks
Gneiss	A banded metamorphic rock formed from granite or similar rocks		earth-rocks
Schist	Metamorphic rock that shines with mica flakes		earth-rocks
Phyllite	Metamorphic rock between slate and schist		earth-rocks
Weathering	Breaking down of rock by wind, water, ice or plants		earth-rocks
Erosion	Moving of weathered material from one place to another		earth-rocks
Deposition	Dropping of sediments in a new place		earth-rocks
Sediment	Small pieces of rock, shell or soil moved by water, wind or ice		earth-rocks
Compaction	Pressing sediments together under weight		earth-rocks
Cementation	Minerals gluing sediments together		earth-rocks
Lithification	The process that turns sediment into rock		earth-rocks
Rock cycle	The never-ending change of rocks from one type to another		earth-rocks
Foliated	Having layers or bands, as in some metamorphic rocks		earth-rocks
Crystal	A solid with atoms arranged in a repeating pattern		earth-rocks
Fossil	The preserved remains or traces of ancient life		earth-rocks
Which rock type usually contains fossils?	Sedimentary		earth-rocks
Strata	Layers of sedimentary rock		earth-rocks
Law of superposition	In undisturbed layers, the oldest rock is at the bottom		earth-rocks
Core sample	A tube of rock or ice pulled from the ground for study		earth-rocks
Geologist	A scientist who studies Earth and its rocks		earth-rocks
Petrologist	A scientist who studies rocks		earth-rocks
Soil	A mix of weathered rock, organic matter, water and air		earth-rocks
Humus	Dark, rich decayed plant and animal matter in soil		earth-rocks
Topsoil	The top soil layer, rich in nutrients		earth-rocks
Bedrock	Solid rock beneath soil		earth-rocks
Clay	The smallest soil particles		earth-rocks
Silt	Soil particles of medium size		earth-rocks
Sand	Soil particles larger than silt and smaller than gravel		earth-rocks
Loam	A balanced soil of sand, silt and clay		earth-rocks
Frost wedging	Water freezing in cracks and splitting rock		earth-rocks
Chemical weathering	Rock changed by chemical reactions, like rusting		earth-rocks
Physical (mechanical) weathering	Rock broken into smaller pieces without chemical change		earth-rocks
Delta	Sediment fan built where a river meets a larger body of water		earth-rocks
Glacier	A large moving mass of ice that carves the land		earth-rocks
Rock that forms from lava cooling	Igneous		earth-rocks
Rock that forms from heat and pressure on other rocks	Metamorphic		earth-rocks
Rock that forms in layers	Sedimentary		earth-rocks
Water cycle	The continuous movement of water between Earth and the air		earth-water-cycle-oceans
Evaporation	Liquid water heated by the Sun turns into vapor		earth-water-cycle-oceans
Transpiration	Plants releasing water vapor from their leaves		earth-water-cycle-oceans
Condensation	Water vapor cools and forms tiny droplets, making clouds		earth-water-cycle-oceans
Precipitation	Water falling as rain, snow, sleet or hail		earth-water-cycle-oceans
Collection	Water gathering in oceans, lakes, rivers and underground		earth-water-cycle-oceans
Runoff	Water flowing over the land into streams and rivers		earth-water-cycle-oceans
Groundwater	Water stored underground in soil and rock		earth-water-cycle-oceans
Aquifer	An underground layer of rock that holds water		earth-water-cycle-oceans
Water table	The top of the groundwater		earth-water-cycle-oceans
Infiltration	Water soaking into the ground		earth-water-cycle-oceans
Surface water	Water in rivers, lakes and streams		earth-water-cycle-oceans
What gives energy to the water cycle?	The Sun		earth-water-cycle-oceans
Freshwater	Water with very little salt		earth-water-cycle-oceans
Saltwater	Water with lots of dissolved salt		earth-water-cycle-oceans
Percent of Earth's water that is fresh, about	3 percent		earth-water-cycle-oceans
Where is most of Earth's fresh water stored?	In glaciers and ice caps		earth-water-cycle-oceans
Five oceans	Pacific, Atlantic, Indian, Southern and Arctic		earth-water-cycle-oceans
Largest ocean	Pacific		earth-water-cycle-oceans
Smallest ocean	Arctic		earth-water-cycle-oceans
Deepest known point in the ocean	Challenger Deep in the Mariana Trench		earth-water-cycle-oceans
Salinity	How salty water is		earth-water-cycle-oceans
Average salinity of seawater	About 3.5 percent		earth-water-cycle-oceans
Tide	The daily rise and fall of sea level		earth-water-cycle-oceans
What causes tides?	The pull of the Moon's and Sun's gravity		earth-water-cycle-oceans
High tide	When the water reaches its highest level		earth-water-cycle-oceans
Low tide	When the water reaches its lowest level		earth-water-cycle-oceans
Spring tide	A tide with the biggest range, at new and full moon		earth-water-cycle-oceans
Neap tide	A tide with the smallest range, at quarter moons		earth-water-cycle-oceans
Wave	Energy moving through water		earth-water-cycle-oceans
What makes most ocean waves?	Wind		earth-water-cycle-oceans
Current	A steady flow of water in the ocean		earth-water-cycle-oceans
Gulf Stream	A warm current that flows from the Gulf of Mexico up the US coast		earth-water-cycle-oceans
Upwelling	Cold, nutrient-rich water rising to the surface		earth-water-cycle-oceans
Continental shelf	The shallow part of the seafloor near a continent		earth-water-cycle-oceans
Continental slope	The steep drop from the shelf to the deep ocean		earth-water-cycle-oceans
Abyssal plain	The flat deep ocean floor		earth-water-cycle-oceans
Seamount	An underwater mountain		earth-water-cycle-oceans
Sunlight zone	The top layer of the ocean where light reaches		earth-water-cycle-oceans
Twilight zone	The ocean layer with dim light, about 200 to 1,000 meters deep		earth-water-cycle-oceans
Midnight zone	The deep ocean layer with no sunlight		earth-water-cycle-oceans
Hadal zone	The deepest ocean zone, in trenches		earth-water-cycle-oceans
Oceanography	The study of the ocean		earth-water-cycle-oceans
Sonar	Uses sound to map the seafloor		earth-water-cycle-oceans
Submersible	A small underwater vehicle for deep dives		earth-water-cycle-oceans
Hydrothermal vent	A crack in the seafloor that spews hot water		earth-water-cycle-oceans
Coral reef	An ocean ecosystem built by tiny coral animals		earth-water-cycle-oceans
Mangrove	A tree that grows in salty coastal water		earth-water-cycle-oceans
Plankton	Tiny life that drifts in the ocean		earth-water-cycle-oceans
Kelp forest	A large underwater forest of giant seaweed		earth-water-cycle-oceans
Why is seawater not good to drink?	It has too much salt for our bodies		earth-water-cycle-oceans
Desalination	Removing salt from seawater		earth-water-cycle-oceans
Water pollution	Harmful substances in water		earth-water-cycle-oceans
Oil spill	Oil leaking into the sea, hurting wildlife		earth-water-cycle-oceans
Ocean acidification	The ocean becoming more acidic as it absorbs carbon dioxide		earth-water-cycle-oceans
Coastal erosion	Waves wearing away the shoreline		earth-water-cycle-oceans
Wetland	Land soaked with water, like a marsh or swamp		earth-water-cycle-oceans
Why are wetlands important?	They filter water and shelter many animals		earth-water-cycle-oceans
Reservoir	A man-made lake that stores water		earth-water-cycle-oceans
Dam	A wall built across a river to hold water		earth-water-cycle-oceans
Weather	What the air outside is like at a certain time and place		earth-weather
Climate	The average weather of a place over many years		earth-weather
Meteorologist	A scientist who studies and forecasts weather		earth-weather
Atmosphere	The layer of gases around Earth		earth-weather
Temperature	How hot or cold something is		earth-weather
Humidity	The amount of water vapor in the air		earth-weather
Precipitation	Water falling from clouds: rain, snow, sleet or hail		earth-weather
Rain	Liquid water drops falling from clouds		earth-weather
Snow	Ice crystals that fall in flakes		earth-weather
Sleet	Frozen raindrops		earth-weather
Hail	Balls of ice that fall from thunderstorms		earth-weather
Freezing rain	Rain that freezes on contact with cold surfaces		earth-weather
Fog	A cloud at ground level		earth-weather
Dew	Water droplets that condense on cool surfaces overnight		earth-weather
Frost	Ice crystals on surfaces below freezing		earth-weather
Wind	Moving air		earth-weather
Air pressure	The weight of air pressing on the surface		earth-weather
High pressure	Usually brings clear, calm weather		earth-weather
Low pressure	Usually brings clouds and storms		earth-weather
Front	The boundary between two air masses		earth-weather
Cold front	Cold air pushes under warm air, often bringing storms		earth-weather
Warm front	Warm air slides over cold air, often bringing steady rain		earth-weather
Stationary front	A front that stays in the same place		earth-weather
Air mass	A large body of air with similar temperature and moisture		earth-weather
Thunderstorm	A storm with thunder, lightning and heavy rain		earth-weather
Lightning	A giant spark of electricity in the sky		earth-weather
Thunder	The sound made by lightning heating the air		earth-weather
Tornado	A rotating column of air that touches the ground		earth-weather
Hurricane	A huge tropical storm with strong winds		earth-weather
Typhoon	Name for a hurricane in the western Pacific		earth-weather
Cyclone	Name for a hurricane in the Indian Ocean		earth-weather
Blizzard	A snowstorm with strong wind and low visibility		earth-weather
Drought	A long time with little rain		earth-weather
Flood	Water covering land that is usually dry		earth-weather
Heat wave	A long period of unusually hot weather		earth-weather
Monsoon	A seasonal wind that brings heavy rains		earth-weather
Tropical storm	A storm with winds of 39 to 73 miles per hour		earth-weather
Eye of a hurricane	The calm center		earth-weather
Storm surge	A rise of sea water pushed ashore by a storm		earth-weather
Water cycle	Water moving through evaporation, condensation and precipitation		earth-weather
Evaporation	Liquid water turning into vapor		earth-weather
Condensation	Water vapor turning into liquid		earth-weather
Dew point	The temperature at which air becomes saturated and dew forms		earth-weather
Forecast	A prediction of future weather		earth-weather
Thermometer	Measures temperature		earth-weather
Barometer	Measures air pressure		earth-weather
Anemometer	Measures wind speed		earth-weather
Wind vane	Shows wind direction		earth-weather
Rain gauge	Measures rainfall		earth-weather
Hygrometer	Measures humidity		earth-weather
Weather balloon	A balloon carrying instruments up into the air		earth-weather
Doppler radar	Radar that detects rain and storm movement		earth-weather
Satellite	A spacecraft that photographs clouds and weather from above		earth-weather
Beaufort scale	A scale for describing wind strength		earth-weather
Saffir-Simpson scale	Rates hurricanes from category 1 to 5		earth-weather
Enhanced Fujita scale	Rates tornado damage from EF0 to EF5		earth-weather
Celsius	A temperature scale where water freezes at 0 and boils at 100		earth-weather
Fahrenheit	A temperature scale where water freezes at 32 and boils at 212		earth-weather
Jet stream	A fast narrow current of wind high in the atmosphere		earth-weather
Coriolis effect	The turning of winds and currents caused by Earth's rotation		earth-weather
El Nino	A pattern of warmer than normal Pacific Ocean water that changes weather worldwide		earth-weather
Rainbow	Arc of colors made when sunlight passes through water drops		earth-weather
Microclimate	The climate of a small area that differs from nearby areas		earth-weather
Lake-effect snow	Snow made when cold air passes over warm lake water		earth-weather
Environment	Everything around a living thing		environmental-science
Natural resource	A material from nature that people use		environmental-science
Renewable resource	A resource that can be replaced naturally, like sunlight and wind		environmental-science
Nonrenewable resource	A resource that cannot be replaced quickly, like oil		environmental-science
Conservation	Protecting and using resources wisely		environmental-science
Reduce, reuse, recycle	Use less, use things again, make new things from old ones		environmental-science
Recycling	Turning used materials into new products		environmental-science
Compost	Decayed food and plant waste that enriches soil		environmental-science
Landfill	A place where trash is buried		environmental-science
Biodegradable	Able to be broken down by living things		environmental-science
Pollution	Harmful materials added to air, water or land		environmental-science
Air pollution	Harmful gases and particles in the air		environmental-science
Water pollution	Harmful substances in water		environmental-science
Soil pollution	Harmful chemicals in the ground		environmental-science
Noise pollution	Loud sounds that harm health or wildlife		environmental-science
Light pollution	Too much artificial light at night		environmental-science
Smog	Smoky fog caused by air pollution		environmental-science
Acid rain	Rain made acidic by pollution		environmental-science
Ozone layer	Layer high in the air that blocks harmful UV rays		environmental-science
Greenhouse effect	Gases in the air trapping heat near Earth		environmental-science
Greenhouse gases	Carbon dioxide, methane and water vapor		environmental-science
Global warming	The rise in Earth's average temperature		environmental-science
Climate change	Long-term change in Earth's weather patterns		environmental-science
Fossil fuels	Coal, oil and natural gas		environmental-science
Carbon footprint	The amount of carbon dioxide caused by a person or activity		environmental-science
Deforestation	Cutting down large areas of forest		environmental-science
Reforestation	Planting trees again		environmental-science
Habitat loss	When animals lose their natural homes		environmental-science
Endangered species	A species at risk of dying out		environmental-science
Extinction	When a species dies out completely		environmental-science
Biodiversity	The variety of life in a place		environmental-science
Invasive species	A species that spreads and harms its new home		environmental-science
Overfishing	Catching fish faster than they can be replaced		environmental-science
Overpopulation	Too many people or animals for resources to support		environmental-science
Erosion	Soil carried away by wind or water		environmental-science
Desertification	Land turning into desert		environmental-science
Drought	A long time without much rain		environmental-science
Water conservation	Using water carefully		environmental-science
Watershed	Land area that drains to a river or lake		environmental-science
Oil spill	Oil leaking into water, harming wildlife		environmental-science
Plastic pollution	Plastic trash in land and oceans		environmental-science
Microplastics	Tiny pieces of plastic less than 5 millimeters		environmental-science
Single-use plastic	Plastic items thrown away after one use		environmental-science
Sustainable	Meeting needs without using up resources for the future		environmental-science
Renewable energy	Energy from sources like sun, wind and water		environmental-science
Solar power	Electricity from sunlight		environmental-science
Wind power	Electricity from wind turbines		environmental-science
Hydropower	Electricity from moving water		environmental-science
Geothermal energy	Heat from within the Earth		environmental-science
Energy efficiency	Using less energy for the same job		environmental-science
Organic farming	Growing food without synthetic chemicals		environmental-science
Pesticide	A chemical that kills pests		environmental-science
Fertilizer	Material added to soil to help plants grow		environmental-science
Runoff	Rain or irrigation water that flows over land carrying pollutants		environmental-science
Eutrophication	Too many nutrients in water causing algae to take over		environmental-science
Wetlands	Land covered with shallow water that cleans water and shelters wildlife		environmental-science
National park	Protected land for nature and people to enjoy		environmental-science
Wildlife refuge	A protected area for wildlife		environmental-science
Who created National Parks in the US?	Congress; Yellowstone became the first in 1872		environmental-science
Earth Day	April 22, a day to protect the environment		environmental-science
EPA	The US Environmental Protection Agency, founded in 1970		environmental-science
Rachel Carson	Wrote Silent Spring in 1962, about pesticides		environmental-science
Ecosystem services	Free benefits nature gives us, like clean water and pollination		environmental-science
Pollinator	An animal that helps plants make seeds, like bees		environmental-science
Food miles	How far food travels before you eat it		environmental-science
Food waste	Edible food that gets thrown away		environmental-science
Green roof	A roof covered with plants		environmental-science
Electric vehicle	A vehicle powered by electricity instead of gasoline		environmental-science
Public transportation	Buses and trains that carry many people		environmental-science
Zero waste	Trying to send nothing to landfill		environmental-science
Ecological footprint	How much of Earth's resources a person uses		environmental-science
Blue whale	The largest animal ever known; eats tiny krill		ocean-life
Humpback whale	A whale famous for songs and breaching		ocean-life
Orca (killer whale)	A large black and white dolphin that hunts in pods		ocean-life
Sperm whale	The largest toothed whale; dives very deep		ocean-life
Beluga whale	A small white whale of Arctic waters		ocean-life
Narwhal	A whale with a long spiral tusk		ocean-life
Dolphin	A smart, social marine mammal that uses echolocation		ocean-life
Porpoise	A small relative of dolphins with a blunt snout		ocean-life
Manatee	A gentle, slow marine mammal that eats plants		ocean-life
Sea otter	A mammal that floats on its back and uses tools to crack shells		ocean-life
Walrus	A large Arctic mammal with tusks		ocean-life
Seal	A marine mammal with flippers and no external ear flaps in true seals		ocean-life
Sea lion	A marine mammal with ear flaps and large front flippers		ocean-life
Polar bear	An Arctic marine mammal that hunts on sea ice		ocean-life
Great white shark	A large predator shark		ocean-life
Whale shark	The largest fish; eats plankton		ocean-life
Hammerhead shark	A shark with a wide, flat head		ocean-life
Manta ray	A giant, wing-like filter feeder		ocean-life
Stingray	A flat fish with a stinging barb on its tail		ocean-life
Clownfish	An orange and white fish that lives among anemones		ocean-life
Seahorse	A fish where the male carries the babies		ocean-life
Pufferfish	A fish that swells with water when threatened		ocean-life
Swordfish	A fast fish with a long flat bill		ocean-life
Tuna	A fast, strong fish important for food		ocean-life
Salmon	A fish that swims from the sea up rivers to spawn		ocean-life
Eel	A long, snake-like fish		ocean-life
Anglerfish	A deep-sea fish with a glowing lure		ocean-life
Flying fish	A fish that glides above the water		ocean-life
Jellyfish	A soft sea animal with stinging tentacles, no brain or heart		ocean-life
Octopus	A smart mollusk with eight arms		ocean-life
Squid	A mollusk with eight arms and two long tentacles		ocean-life
Giant squid	A deep-sea squid with the largest eyes in the animal world		ocean-life
Cuttlefish	A relative of squid that changes color quickly		ocean-life
Nautilus	A shelled cephalopod with a spiral shell		ocean-life
Starfish (sea star)	A spiny-skinned animal with arms		ocean-life
Sea urchin	A spiny round animal		ocean-life
Sea cucumber	A soft, sausage-shaped animal on the seafloor		ocean-life
Crab	A crustacean with claws and a hard shell		ocean-life
Lobster	A large crustacean with big claws		ocean-life
Shrimp	A small crustacean with a curved body		ocean-life
Krill	Tiny shrimp-like animals eaten by whales		ocean-life
Barnacle	A crustacean that sticks to rocks and boats		ocean-life
Hermit crab	A crab that lives inside a borrowed shell		ocean-life
Sea turtle	A reptile that lives in the ocean and lays eggs on beaches		ocean-life
Sea snake	A venomous snake adapted to the sea		ocean-life
Marine iguana	A lizard that feeds on algae in the sea, found in the Galapagos		ocean-life
Penguin	A flightless bird that swims		ocean-life
Albatross	A seabird with a very long wingspan		ocean-life
Pelican	A seabird with a throat pouch		ocean-life
Coral	A tiny animal that builds a hard skeleton, forming reefs		ocean-life
Sponge	A simple animal that filters water		ocean-life
Sea anemone	A soft animal with stinging tentacles		ocean-life
Seaweed	Algae that grows in the sea		ocean-life
Kelp	A large brown seaweed that forms forests		ocean-life
Plankton	Tiny living things that drift in the sea		ocean-life
Mollusk examples	Clams, snails, oysters and octopuses		ocean-life
Great Barrier Reef	The world's largest coral reef system, off Australia		ocean-life
Bioluminescence	Light made by living things, as in jellyfish and anglerfish		ocean-life
Pod	A group of whales or dolphins		ocean-life
School	A group of fish		ocean-life
Baleen	Plates in some whales' mouths that filter food		ocean-life
Blowhole	The nostril on top of a whale's head		ocean-life
Echolocation	Using sound echoes to find prey		ocean-life
Gills	Organs fish use to get oxygen from water		ocean-life
Fins	Body parts that help fish steer and balance		ocean-life
Ink	A dark fluid octopuses squirt to hide		ocean-life
Tide pool	A pocket of water left behind on a rocky shore at low tide		ocean-life
Intertidal zone	The shore area between high and low tide		ocean-life
Deep sea	The dark, cold part of the ocean far below the surface		ocean-life
Mariana Trench	The deepest place in the ocean		ocean-life
Food chain in the sea	Phytoplankton, zooplankton, small fish, larger fish and sharks or whales		ocean-life
Overfishing	Catching fish faster than they can reproduce		ocean-life
Electric charge	A property of matter that can be positive or negative		phys-electricity-magnetism
Like charges	Repel each other		phys-electricity-magnetism
Opposite charges	Attract each other		phys-electricity-magnetism
Proton charge	Positive		phys-electricity-magnetism
Electron charge	Negative		phys-electricity-magnetism
Neutron charge	None; neutral		phys-electricity-magnetism
Static electricity	Charge that builds up on an object		phys-electricity-magnetism
Example of static electricity	A balloon sticking to your hair after rubbing		phys-electricity-magnetism
Lightning	A huge spark of static electricity in clouds		phys-electricity-magnetism
Current	The flow of electric charge		phys-electricity-magnetism
Voltage	The push that moves charge in a circuit		phys-electricity-magnetism
Resistance	How much a material resists current		phys-electricity-magnetism
Circuit	A complete path for electricity		phys-electricity-magnetism
Open circuit	A circuit with a break, so no current flows		phys-electricity-magnetism
Closed circuit	A complete loop where current flows		phys-electricity-magnetism
Series circuit	Parts connected in one path; if one breaks all stop		phys-electricity-magnetism
Parallel circuit	Parts connected on separate paths; if one breaks others keep working		phys-electricity-magnetism
Switch	A device that opens or closes a circuit		phys-electricity-magnetism
Battery	A source that provides electrical energy from chemical reactions		phys-electricity-magnetism
Cell	One unit of a battery		phys-electricity-magnetism
Wire	A thin strand of metal that carries current		phys-electricity-magnetism
Conductor	A material that lets current flow easily		phys-electricity-magnetism
Insulator	A material that blocks current		phys-electricity-magnetism
Examples of conductors	Copper, silver, aluminum and water with salt		phys-electricity-magnetism
Examples of insulators	Rubber, plastic, glass and wood		phys-electricity-magnetism
Fuse	A safety part that melts and breaks the circuit if the current is too high		phys-electricity-magnetism
Circuit breaker	A switch that shuts off a circuit when it carries too much current		phys-electricity-magnetism
Ground	A path that carries extra current safely into the Earth		phys-electricity-magnetism
Alternating current (AC)	Current that changes direction back and forth; used in homes		phys-electricity-magnetism
Direct current (DC)	Current that flows one way; from batteries		phys-electricity-magnetism
Generator	A device that turns motion into electricity		phys-electricity-magnetism
Transformer	A device that changes the voltage of AC		phys-electricity-magnetism
Resistor	A part that limits the current in a circuit		phys-electricity-magnetism
Capacitor	A part that stores electric charge		phys-electricity-magnetism
Diode	A part that lets current flow one way		phys-electricity-magnetism
Transistor	A tiny switch or amplifier in electronics		phys-electricity-magnetism
Semiconductor	A material, like silicon, that conducts better than an insulator but less than a metal		phys-electricity-magnetism
Magnet	An object that attracts iron and has a north and south pole		phys-electricity-magnetism
Magnetic pole	The end of a magnet where force is strongest		phys-electricity-magnetism
Like poles	Repel		phys-electricity-magnetism
Opposite poles	Attract		phys-electricity-magnetism
Magnetic field	The region around a magnet where its force acts		phys-electricity-magnetism
Magnetic materials	Iron, nickel and cobalt		phys-electricity-magnetism
Compass	Needle magnet that points to Earth's magnetic north		phys-electricity-magnetism
Earth's magnetic field	Produced by moving molten iron in the outer core		phys-electricity-magnetism
Electromagnet	A magnet made by running current through a coil, often around an iron core		phys-electricity-magnetism
Electromagnetic induction	Making current by changing a magnetic field near a wire		phys-electricity-magnetism
Who discovered electromagnetic induction in 1831?	Michael Faraday		phys-electricity-magnetism
Who showed in 1820 that electric current creates a magnetic field?	Hans Christian Oersted		phys-electricity-magnetism
Who flew a kite in a storm in a famous experiment?	Benjamin Franklin		phys-electricity-magnetism
Who invented the practical light bulb in 1879?	Thomas Edison		phys-electricity-magnetism
Who built the first battery around 1800?	Alessandro Volta		phys-electricity-magnetism
Aurora	Glowing lights where charged particles from the Sun hit Earth's atmosphere near the poles		phys-electricity-magnetism
Electric motor	A device that turns electricity into motion		phys-electricity-magnetism
Solenoid	A coil of wire that makes a magnetic field when current flows		phys-electricity-magnetism
Short circuit	An unplanned path with low resistance that can cause too much current		phys-electricity-magnetism
Why should you never put a fork in a socket?	Metal conducts electricity and can cause serious harm		phys-electricity-magnetism
Staying safe in a storm	Go indoors and stay away from windows and water		phys-electricity-magnetism
Why are power lines high up?	To keep the dangerous electricity away from people		phys-electricity-magnetism
Energy	The ability to cause change or do work		phys-energy
Kinetic energy	Energy of movement		phys-energy
Potential energy	Stored energy		phys-energy
Mechanical energy	Kinetic plus potential energy of an object		phys-energy
Chemical energy	Energy stored in food, fuel and batteries		phys-energy
Electrical energy	Energy of moving electric charges		phys-energy
Thermal energy	Energy of moving particles; felt as heat		phys-energy
Light (radiant) energy	Energy carried by electromagnetic waves		phys-energy
Sound energy	Energy carried by vibrations		phys-energy
Nuclear energy	Energy stored in an atom's nucleus		phys-energy
Elastic energy	Energy stored in a stretched rubber band or spring		phys-energy
Gravitational energy	Energy stored by an object that is high up		phys-energy
Energy change in a lamp	Electrical to light and heat		phys-energy
Energy change in a toaster	Electrical to heat		phys-energy
Energy change in a car engine	Chemical to thermal to motion		phys-energy
Energy change in a solar cell	Light to electrical		phys-energy
Energy change in a battery	Chemical to electrical		phys-energy
Energy change in a microphone	Sound to electrical		phys-energy
Energy change in a speaker	Electrical to sound		phys-energy
Energy change in a plant	Light to chemical		phys-energy
Energy change in a falling ball	Potential to kinetic		phys-energy
Energy change in rubbing hands	Motion to heat		phys-energy
Energy change in a hydroelectric dam	Gravitational potential to kinetic to electrical		phys-energy
Renewable energy	Energy from sources that can be replaced naturally		phys-energy
Nonrenewable energy	Energy from sources that cannot be replaced soon		phys-energy
Fossil fuels	Coal, oil and natural gas made from ancient living things		phys-energy
Coal	A solid fossil fuel made from ancient plants		phys-energy
Petroleum	Liquid fossil fuel also called crude oil		phys-energy
Natural gas	Fossil fuel made mostly of methane		phys-energy
Solar energy	Energy from the Sun		phys-energy
Wind energy	Energy from moving air that turns turbines		phys-energy
Hydroelectric power	Electricity from moving water		phys-energy
Geothermal energy	Heat from inside the Earth		phys-energy
Biomass	Energy from burning plants or waste		phys-energy
Biofuel	Fuel made from plants, like ethanol		phys-energy
Tidal energy	Energy from the rise and fall of ocean tides		phys-energy
Nuclear power	Electricity from splitting atoms in a reactor		phys-energy
Uranium	The fuel used in most nuclear plants		phys-energy
Photovoltaic cell	A solar cell that makes electricity from light		phys-energy
Turbine	A wheel that spins to run a generator		phys-energy
Generator	A machine that turns motion into electricity		phys-energy
Power plant	A facility that makes electricity		phys-energy
Energy conservation	Using less energy		phys-energy
Energy efficiency	Getting the same job done using less energy		phys-energy
Greenhouse gas	A gas that traps heat in the atmosphere, such as carbon dioxide		phys-energy
Sun's energy source	Nuclear fusion of hydrogen into helium		phys-energy
Law of conservation of energy	Energy is never made or destroyed, only changed		phys-energy
Where does most of Earth's energy come from?	The Sun		phys-energy
Joule	The unit of energy		phys-energy
Watt	A rate of energy use, one joule per second		phys-energy
Kilowatt-hour	A unit of electrical energy used on a power bill		phys-energy
Calorie	A unit of energy in food (the Calorie on labels is 1,000 small calories)		phys-energy
Grid	The network that delivers electricity to homes		phys-energy
Battery	Stores chemical energy and gives electrical energy		phys-energy
Fuel cell	A device that makes electricity from a reaction such as hydrogen with oxygen		phys-energy
Wasted energy	Energy that ends up as unwanted heat		phys-energy
Insulation	Material that slows heat loss		phys-energy
LED	A light bulb that uses much less energy than an old incandescent bulb		phys-energy
Passive solar	Using building design to gather the Sun's heat		phys-energy
Smart meter	A meter that tracks electricity use in detail		phys-energy
What is a force?	A push or a pull		phys-forces-motion
What unit measures force?	The newton		phys-forces-motion
What force pulls objects toward Earth?	Gravity		phys-forces-motion
What does friction do?	Slows or stops objects that slide against each other		phys-forces-motion
Which surface has more friction, ice or sandpaper?	Sandpaper		phys-forces-motion
How can you reduce friction?	Use oil, wheels or a smooth surface		phys-forces-motion
Types of friction	Static, sliding, rolling and fluid		phys-forces-motion
Static friction	Friction that keeps a resting object from moving		phys-forces-motion
Sliding friction	Friction between surfaces sliding over each other		phys-forces-motion
Rolling friction	Friction when an object rolls; usually smaller than sliding		phys-forces-motion
Air resistance	A force that slows things moving through air		phys-forces-motion
Magnetic force	A push or pull between magnets		phys-forces-motion
Normal force	The push of a surface upward on an object resting on it		phys-forces-motion
Tension	A pulling force through a rope or string		phys-forces-motion
Applied force	A force given to an object by a person or thing		phys-forces-motion
Buoyant force	The upward push of water on an object		phys-forces-motion
Why does a feather fall slower than a rock in air?	Air resistance affects it more		phys-forces-motion
Would a feather and a hammer fall together on the Moon?	Yes, with no air they fall at the same rate; astronaut David Scott showed this in 1971		phys-forces-motion
Mass vs weight	Mass is the amount of matter; weight is the pull of gravity on it		phys-forces-motion
Is your mass different on the Moon?	No; your weight is, because gravity is weaker		phys-forces-motion
How much is gravity on the Moon compared to Earth?	About one-sixth		phys-forces-motion
Balanced forces	Forces equal and opposite; no change in motion		phys-forces-motion
Unbalanced forces	Forces that change an object's motion		phys-forces-motion
Inertia	The tendency of objects to keep doing what they're doing		phys-forces-motion
Why do you lurch forward when a car brakes?	Your body's inertia keeps it moving forward		phys-forces-motion
Newton's first law in short	Objects at rest stay at rest and objects in motion stay in motion unless a force acts		phys-forces-motion
Newton's second law in short	More force means more acceleration; more mass means less		phys-forces-motion
Newton's third law in short	Every action has an equal and opposite reaction		phys-forces-motion
Example of Newton's third law	A rocket pushes gas down and the gas pushes the rocket up		phys-forces-motion
Speed	How fast something moves		phys-forces-motion
Velocity	Speed with a direction		phys-forces-motion
Acceleration	Changing speed or direction		phys-forces-motion
Is a car turning at constant speed accelerating?	Yes, because its direction is changing		phys-forces-motion
Free fall	Falling with only gravity acting		phys-forces-motion
How fast do falling objects accelerate on Earth?	About 9.8 meters per second every second		phys-forces-motion
Terminal velocity	The top speed of a falling object when air resistance balances weight		phys-forces-motion
Projectile	An object launched and moving through the air		phys-forces-motion
Momentum	How hard it is to stop a moving object: mass times velocity		phys-forces-motion
Collision	When two objects hit each other		phys-forces-motion
Elastic collision	Objects bounce and kinetic energy is kept		phys-forces-motion
Inelastic collision	Objects crumple or stick together and some energy changes form		phys-forces-motion
Centripetal force	A force pulling toward the center of a circular path		phys-forces-motion
Centrifugal force	The feeling of being pushed outward in a turn; really inertia		phys-forces-motion
Orbit	The curved path of one object around another due to gravity		phys-forces-motion
Why do planets stay in orbit?	Gravity pulls them toward the Sun while their motion carries them forward		phys-forces-motion
Who described the law of gravity in the 1600s?	Isaac Newton		phys-forces-motion
Who showed that objects of different mass fall at the same rate in a vacuum?	Galileo's ideas led there; later experiments confirmed it		phys-forces-motion
Seat belts protect people by	Slowing the body gradually and holding it in place		phys-forces-motion
Airbags work by	Spreading force over a longer time		phys-forces-motion
Pressure	Force spread over an area		phys-forces-motion
Why do snowshoes help you walk on snow?	They spread weight over a larger area		phys-forces-motion
Torque	A force that causes turning		phys-forces-motion
Equilibrium	A state in which forces are balanced		phys-forces-motion
Speed formula	Speed = distance divided by time		phys-forces-motion
If you travel 100 km in 2 hours, your average speed is	50 km per hour		phys-forces-motion
Reference point	A place or object used to describe an object's position		phys-forces-motion
Newton's first law	An object stays at rest or in steady motion unless acted on by a net force		phys-laws-formulas
Newton's second law	F = m x a		phys-laws-formulas
Newton's third law	For every action there is an equal and opposite reaction		phys-laws-formulas
Speed	speed = distance / time		phys-laws-formulas
Acceleration	a = (final velocity - initial velocity) / time		phys-laws-formulas
Weight	W = m x g		phys-laws-formulas
Momentum	p = m x v		phys-laws-formulas
Work	W = F x d		phys-laws-formulas
Power	P = W / t		phys-laws-formulas
Kinetic energy	KE = 1/2 m v squared		phys-laws-formulas
Gravitational potential energy	PE = m x g x h		phys-laws-formulas
Density	density = mass / volume		phys-laws-formulas
Pressure	P = F / A		phys-laws-formulas
Ohm's law	V = I x R		phys-laws-formulas
Electric power	P = I x V		phys-laws-formulas
Wave speed	v = f x wavelength		phys-laws-formulas
Frequency and period	f = 1 / T		phys-laws-formulas
Universal gravitation	F = G m1 m2 / r squared		phys-laws-formulas
Einstein's mass-energy equivalence	E = m c squared		phys-laws-formulas
Law of conservation of energy	Energy cannot be created or destroyed, only changed in form		phys-laws-formulas
Law of conservation of momentum	Total momentum stays the same in a closed system		phys-laws-formulas
Hooke's law	The force of a spring is proportional to how far it is stretched: F = kx		phys-laws-formulas
Archimedes' principle	The buoyant force equals the weight of the fluid displaced		phys-laws-formulas
Pascal's principle	Pressure applied to a confined fluid is passed on equally		phys-laws-formulas
Bernoulli's principle	Faster-moving fluid has lower pressure		phys-laws-formulas
Boyle's law	At constant temperature, gas pressure goes down as volume goes up		phys-laws-formulas
Charles's law	At constant pressure, gas volume goes up as temperature goes up		phys-laws-formulas
Snell's law	Describes how light bends when it passes between materials		phys-laws-formulas
Law of reflection	The angle of incidence equals the angle of reflection		phys-laws-formulas
Coulomb's law	Electric force depends on charges and on distance squared		phys-laws-formulas
First law of thermodynamics	Energy is conserved; heat and work change internal energy		phys-laws-formulas
Second law of thermodynamics	Heat flows from hot to cold, and entropy tends to increase		phys-laws-formulas
Third law of thermodynamics	A system cannot be cooled to absolute zero in a finite number of steps		phys-laws-formulas
Kepler's first law	Planets orbit in ellipses with the Sun at one focus		phys-laws-formulas
Kepler's second law	A planet sweeps out equal areas in equal times		phys-laws-formulas
Kepler's third law	A planet's orbital period squared is proportional to its distance cubed		phys-laws-formulas
Centripetal acceleration	a = v squared / r		phys-laws-formulas
Average velocity	(final position - starting position) / time		phys-laws-formulas
Distance at constant acceleration from rest	d = 1/2 a t squared		phys-laws-formulas
Final speed from rest	v = a x t		phys-laws-formulas
Series circuit resistance	Total R = R1 + R2 + R3		phys-laws-formulas
Parallel circuit resistance	1/R total = 1/R1 + 1/R2 + ...		phys-laws-formulas
Kinetic energy depends on speed how?	On the square of speed, so doubling speed quadruples KE		phys-laws-formulas
Mechanical advantage	Output force divided by input force		phys-laws-formulas
Efficiency	(useful output / total input) x 100 percent		phys-laws-formulas
Heat energy	Q = m c (change in temperature)		phys-laws-formulas
Specific heat capacity	Heat needed to raise 1 kg of a substance by 1 degree		phys-laws-formulas
Ideal gas law	PV = nRT		phys-laws-formulas
Doppler effect	The pitch or color of a wave changes when the source or observer moves		phys-laws-formulas
Heisenberg uncertainty principle	You cannot know a particle's exact position and momentum at once		phys-laws-formulas
Photon energy	E = h x f (Planck's constant times frequency)		phys-laws-formulas
Torque	Torque = force x distance from the pivot		phys-laws-formulas
Impulse-momentum	Force x time = change in momentum		phys-laws-formulas
Escape velocity	The speed needed to break free of a planet's gravity		phys-laws-formulas
Universal gravitational constant	G, about 6.67 x 10^-11 N m2/kg2		phys-laws-formulas
What makes sound?	Vibrations		phys-light-sound-waves
Can sound travel in space?	No; it needs matter to travel through		phys-light-sound-waves
Does sound travel faster in air or water?	Water		phys-light-sound-waves
Sound travels fastest through	Solids		phys-light-sound-waves
Pitch	How high or low a sound is		phys-light-sound-waves
What determines pitch?	Frequency		phys-light-sound-waves
Volume (loudness)	How strong a sound is; depends on amplitude		phys-light-sound-waves
Unit of loudness	Decibel		phys-light-sound-waves
Echo	A sound that bounces off a surface and comes back		phys-light-sound-waves
Ultrasound	Sound with frequency too high for humans to hear		phys-light-sound-waves
Infrasound	Sound with frequency too low for humans to hear		phys-light-sound-waves
Range of human hearing, roughly	20 to 20,000 hertz		phys-light-sound-waves
Sonar	Using sound echoes to find objects underwater		phys-light-sound-waves
Echolocation	Animals such as bats and dolphins using echoes to find things		phys-light-sound-waves
Speed of sound in air, roughly	343 meters per second		phys-light-sound-waves
Sonic boom	A loud noise made when something travels faster than sound		phys-light-sound-waves
Speed of light	About 300,000 kilometers per second		phys-light-sound-waves
Why do we see lightning before we hear thunder?	Light travels much faster than sound		phys-light-sound-waves
Light travels in	Straight lines		phys-light-sound-waves
Reflection of light	Light bouncing off a surface		phys-light-sound-waves
Refraction of light	Light bending when it enters a new material		phys-light-sound-waves
What does a prism do?	Splits white light into a rainbow of colors		phys-light-sound-waves
Colors of the rainbow in order	Red, orange, yellow, green, blue, indigo, violet		phys-light-sound-waves
Which color of visible light has the longest wavelength?	Red		phys-light-sound-waves
Which color has the shortest wavelength?	Violet		phys-light-sound-waves
Transparent	Lets light pass through clearly		phys-light-sound-waves
Translucent	Lets some light through but scatters it		phys-light-sound-waves
Opaque	Blocks light		phys-light-sound-waves
Shadow	A dark area where an object blocks light		phys-light-sound-waves
Convex lens	A lens thicker in the middle; makes light converge		phys-light-sound-waves
Concave lens	A lens thinner in the middle; makes light spread out		phys-light-sound-waves
Plane mirror	A flat mirror that forms an image the same size as the object		phys-light-sound-waves
Concave mirror	A mirror curved inward, like the inside of a spoon		phys-light-sound-waves
Convex mirror	A mirror curved outward, used as a car side mirror		phys-light-sound-waves
Primary colors of light	Red, green and blue		phys-light-sound-waves
Primary colors of paint (traditional)	Red, yellow and blue		phys-light-sound-waves
Why is the sky blue?	Air scatters blue light more than other colors		phys-light-sound-waves
Why are sunsets red?	Light passes through more air, scattering the blue away		phys-light-sound-waves
Electromagnetic spectrum order, long to short wavelength	Radio, microwave, infrared, visible, ultraviolet, X-ray, gamma ray		phys-light-sound-waves
Radio waves are used for	Radio, TV and phones		phys-light-sound-waves
Microwaves are used for	Cooking and communications		phys-light-sound-waves
Infrared is felt as	Heat		phys-light-sound-waves
Ultraviolet light	Causes sunburn and tanning		phys-light-sound-waves
X-rays are used for	Seeing bones and inside objects		phys-light-sound-waves
Gamma rays	The highest-energy waves		phys-light-sound-waves
Laser	A narrow beam of light of one wavelength		phys-light-sound-waves
Fiber optics	Thin glass fibers that carry light signals		phys-light-sound-waves
Total internal reflection	Light bouncing entirely inside a material like glass or water		phys-light-sound-waves
Mirage	An image caused by light bending in hot air		phys-light-sound-waves
Wave	A disturbance that carries energy		phys-light-sound-waves
Crest	The highest point of a wave		phys-light-sound-waves
Trough	The lowest point of a wave		phys-light-sound-waves
Amplitude	The height of a wave from rest position		phys-light-sound-waves
Wavelength	Distance between two crests		phys-light-sound-waves
Frequency	Waves per second		phys-light-sound-waves
Medium	The material a wave travels through		phys-light-sound-waves
Resonance	A strong vibration when something is pushed at its natural frequency		phys-light-sound-waves
Interference	Waves combining to be bigger or smaller		phys-light-sound-waves
Doppler effect	A siren sounds higher as it approaches and lower as it leaves		phys-light-sound-waves
Simple machine	A tool with few or no moving parts that makes work easier		phys-simple-machines
How many kinds of simple machines are there?	Six		phys-simple-machines
Name the six simple machines	Lever, wheel and axle, pulley, inclined plane, wedge, screw		phys-simple-machines
Lever	A bar that rotates around a point called a fulcrum		phys-simple-machines
Fulcrum	The pivot point of a lever		phys-simple-machines
Effort	The force you apply to a machine		phys-simple-machines
Load (resistance)	The weight a machine moves		phys-simple-machines
First-class lever	Fulcrum is between the effort and the load		phys-simple-machines
Second-class lever	Load is between the fulcrum and the effort		phys-simple-machines
Third-class lever	Effort is between the fulcrum and the load		phys-simple-machines
Example of a first-class lever	A seesaw or a crowbar		phys-simple-machines
Example of a second-class lever	A wheelbarrow or a nutcracker		phys-simple-machines
Example of a third-class lever	A fishing rod, a broom or tweezers		phys-simple-machines
Inclined plane	A flat sloped surface used to raise or lower loads		phys-simple-machines
Example of an inclined plane	A ramp or a slide		phys-simple-machines
Wedge	Two inclined planes put together to split or cut things		phys-simple-machines
Example of a wedge	An axe, knife or doorstop		phys-simple-machines
Screw	An inclined plane wrapped around a cylinder		phys-simple-machines
Example of a screw	A jar lid, a bolt or a light bulb base		phys-simple-machines
Wheel and axle	A wheel joined to a rod so they turn together		phys-simple-machines
Example of a wheel and axle	A doorknob, a steering wheel or a bicycle wheel		phys-simple-machines
Pulley	A wheel with a rope or chain that changes the direction of a pull		phys-simple-machines
Example of a pulley	A flagpole rope, a crane or a window blind		phys-simple-machines
Fixed pulley	A pulley attached in place; changes the direction of force		phys-simple-machines
Movable pulley	A pulley that moves with the load; reduces the force needed		phys-simple-machines
Block and tackle	A system of pulleys that gives a large mechanical advantage		phys-simple-machines
Mechanical advantage	How many times a machine multiplies your effort		phys-simple-machines
Do machines reduce the work done?	No; they make work easier by changing force or direction		phys-simple-machines
What do you give up when you use less force?	You move through a longer distance		phys-simple-machines
Compound machine	Two or more simple machines working together		phys-simple-machines
Example of a compound machine	Scissors, a bicycle or a can opener		phys-simple-machines
Scissors are made of	Levers and wedges		phys-simple-machines
A longer ramp makes it	Easier to push things up, but you push farther		phys-simple-machines
Work	Force times distance		phys-simple-machines
Wheelbarrow	A second-class lever with a wheel and axle		phys-simple-machines
Pliers	Two levers joined together		phys-simple-machines
Bottle opener	A second-class lever		phys-simple-machines
Stairs	A set of inclined planes		phys-simple-machines
Spiral staircase	A kind of screw shape		phys-simple-machines
Zipper	A group of tiny wedges		phys-simple-machines
Chisel	A wedge		phys-simple-machines
Faucet handle	A wheel and axle		phys-simple-machines
Gears	Toothed wheels that turn each other		phys-simple-machines
Ax splitting wood	Uses a wedge to push wood apart		phys-simple-machines
Drill bit	A screw		phys-simple-machines
Teeter-totter	A first-class lever		phys-simple-machines
Baseball bat	A third-class lever		phys-simple-machines
Hammer pulling a nail	A first-class lever		phys-simple-machines
Why is a longer lever arm helpful?	Less effort force is needed to lift the load		phys-simple-machines
Archimedes' famous line about levers	Give me a place to stand and I will move the Earth		phys-simple-machines
Motion	A change in an object's position		phys-terms
Speed	How fast an object moves: distance divided by time		phys-terms
Velocity	Speed in a given direction		phys-terms
Acceleration	How quickly velocity changes		phys-terms
Displacement	The straight-line change in position, with direction		phys-terms
Distance	The total length of the path traveled		phys-terms
Scalar	A quantity with size only, like speed		phys-terms
Vector	A quantity with size and direction, like velocity		phys-terms
Force	A push or a pull		phys-terms
Net force	The total of all forces acting on an object		phys-terms
Balanced forces	Forces that cancel, causing no change in motion		phys-terms
Unbalanced forces	Forces that do not cancel, causing a change in motion		phys-terms
Inertia	An object's resistance to change in its motion		phys-terms
Mass	The amount of matter in an object		phys-terms
Weight	The force of gravity on an object		phys-terms
Gravity	The force that pulls objects with mass toward each other		phys-terms
Friction	A force that resists sliding between surfaces		phys-terms
Air resistance	Friction from air pushing against a moving object		phys-terms
Terminal velocity	The constant speed reached when air resistance equals weight		phys-terms
Momentum	Mass times velocity		phys-terms
Impulse	A force applied over time, changing momentum		phys-terms
Work	Force applied over a distance		phys-terms
Power	The rate of doing work		phys-terms
Energy	The ability to do work or cause change		phys-terms
Kinetic energy	Energy of motion		phys-terms
Potential energy	Stored energy due to position or condition		phys-terms
Gravitational potential energy	Energy stored in an object because of its height		phys-terms
Elastic potential energy	Energy stored in stretched or squeezed objects		phys-terms
Thermal energy	The total kinetic energy of the particles in an object		phys-terms
Heat	Thermal energy moving from hot to cold		phys-terms
Temperature	A measure of the average kinetic energy of particles		phys-terms
Conduction	Heat moving through direct contact		phys-terms
Convection	Heat moving by the flow of fluids		phys-terms
Radiation	Energy traveling as waves, even through empty space		phys-terms
Wave	A disturbance that carries energy		phys-terms
Frequency	The number of waves passing a point per second		phys-terms
Wavelength	The distance from one wave crest to the next		phys-terms
Amplitude	The height of a wave from its rest position		phys-terms
Hertz	The unit of frequency: one wave per second		phys-terms
Reflection	Waves bouncing off a surface		phys-terms
Refraction	Waves bending when they enter a new material		phys-terms
Diffraction	Waves spreading as they pass an edge or opening		phys-terms
Absorption	A material taking in wave energy		phys-terms
Transverse wave	A wave in which particles move up and down across the wave's direction		phys-terms
Longitudinal wave	A wave in which particles move back and forth along the wave's direction		phys-terms
Electromagnetic spectrum	The full range of light waves from radio to gamma rays		phys-terms
Circuit	A closed path for electric current		phys-terms
Current	The flow of electric charge		phys-terms
Voltage	The push that moves charge through a circuit		phys-terms
Resistance	How much a material opposes electric current		phys-terms
Conductor	A material that carries electricity or heat well		phys-terms
Insulator	A material that carries electricity or heat poorly		phys-terms
Magnet	An object that attracts iron and has two poles		phys-terms
Magnetic field	The area around a magnet where it exerts force		phys-terms
Electromagnet	A magnet made by passing current through a coil of wire		phys-terms
Static electricity	A buildup of electric charge on an object		phys-terms
Atom	The smallest unit of an element		phys-terms
Nuclear fission	Splitting a large nucleus into smaller ones, releasing energy		phys-terms
Nuclear fusion	Joining small nuclei into a larger one, releasing energy		phys-terms
Radioactive decay	An unstable nucleus giving off particles or energy		phys-terms
Pressure	Force per unit area		phys-terms
Buoyancy	The upward push of a fluid on an object		phys-terms
Density	Mass per unit of volume		phys-terms
Torque	A twisting force		phys-terms
Centripetal force	A force that pulls an object toward the center of a circle		phys-terms
Projectile	An object thrown or launched and moving under gravity		phys-terms
Free fall	Falling with only gravity acting		phys-terms
Efficiency	The share of input energy that does useful work		phys-terms
Length	meter (m)		phys-units-symbols
Mass	kilogram (kg)		phys-units-symbols
Time	second (s)		phys-units-symbols
Temperature (SI)	kelvin (K)		phys-units-symbols
Electric current	ampere (A)		phys-units-symbols
Amount of substance	mole (mol)		phys-units-symbols
Luminous intensity	candela (cd)		phys-units-symbols
Force	newton (N)		phys-units-symbols
Energy and work	joule (J)		phys-units-symbols
Power	watt (W)		phys-units-symbols
Pressure	pascal (Pa)		phys-units-symbols
Frequency	hertz (Hz)		phys-units-symbols
Electric charge	coulomb (C)		phys-units-symbols
Voltage	volt (V)		phys-units-symbols
Electrical resistance	ohm		phys-units-symbols
Capacitance	farad (F)		phys-units-symbols
Magnetic flux density	tesla (T)		phys-units-symbols
Inductance	henry (H)		phys-units-symbols
Radioactivity	becquerel (Bq)		phys-units-symbols
Absorbed radiation dose	gray (Gy)		phys-units-symbols
Conductance	siemens (S)		phys-units-symbols
Magnetic flux	weber (Wb)		phys-units-symbols
Speed	meters per second (m/s)		phys-units-symbols
Acceleration	meters per second squared (m/s2)		phys-units-symbols
Density	kilograms per cubic meter (kg/m3)		phys-units-symbols
Momentum	kilogram meters per second (kg m/s)		phys-units-symbols
Area	square meters (m2)		phys-units-symbols
Volume	cubic meters (m3)		phys-units-symbols
Symbol for the ohm	The Greek letter omega		phys-units-symbols
Symbol for velocity	v		phys-units-symbols
Symbol for acceleration	a		phys-units-symbols
Symbol for mass	m		phys-units-symbols
Symbol for force	F		phys-units-symbols
Symbol for energy	E		phys-units-symbols
Symbol for work	W		phys-units-symbols
Symbol for power	P		phys-units-symbols
Symbol for time	t		phys-units-symbols
Symbol for distance	d		phys-units-symbols
Symbol for pressure	P or p		phys-units-symbols
Symbol for density	The Greek letter rho		phys-units-symbols
Symbol for wavelength	The Greek letter lambda		phys-units-symbols
Symbol for frequency	f		phys-units-symbols
Symbol for voltage	V		phys-units-symbols
Symbol for current	I		phys-units-symbols
Symbol for resistance	R		phys-units-symbols
Unit named for the discoverer of gravity's laws	Newton		phys-units-symbols
Unit named for an English brewer who studied heat and work	Joule		phys-units-symbols
Unit named for the Scottish engineer James Watt	Watt		phys-units-symbols
Unit named for Blaise Pascal	Pascal		phys-units-symbols
Unit named for Heinrich Hertz	Hertz		phys-units-symbols
Unit named for Alessandro Volta	Volt		phys-units-symbols
Unit named for Andre-Marie Ampere	Ampere		phys-units-symbols
Unit named for Georg Ohm	Ohm		phys-units-symbols
Unit named for Lord Kelvin	Kelvin		phys-units-symbols
Unit named for Nikola Tesla	Tesla		phys-units-symbols
Speed of light in a vacuum	About 300,000 kilometers per second (3.00 x 10^8 m/s)		phys-units-symbols
Acceleration due to gravity on Earth	About 9.8 m/s2		phys-units-symbols
Freezing point of water in Celsius	0 degrees C		phys-units-symbols
Boiling point of water in Kelvin	373 K		phys-units-symbols
Absolute zero in Celsius	-273.15 degrees C		phys-units-symbols
Speed of sound in air, about	343 meters per second at 20 degrees C		phys-units-symbols
Calorie	A unit of energy; 1 calorie is about 4.18 joules		phys-units-symbols
Horsepower	A unit of power; about 746 watts		phys-units-symbols
Kilowatt-hour	A unit of energy equal to 3.6 million joules		phys-units-symbols
Electronvolt	A tiny unit of energy used for particles		phys-units-symbols
Light-year	The distance light travels in one year		phys-units-symbols
Astronomical unit	The average distance from Earth to the Sun		phys-units-symbols
Parsec	A unit of distance equal to about 3.26 light-years		phys-units-symbols
Atmosphere (atm)	A unit of pressure; the typical air pressure at sea level		phys-units-symbols
Decibel	A unit used for the loudness of sound		phys-units-symbols
Isaac Newton	Laws of motion and universal gravitation		sci-famous-scientists
Albert Einstein	Theory of relativity and E = mc squared		sci-famous-scientists
Marie Curie	Discovered polonium and radium; studied radioactivity; won two Nobel Prizes		sci-famous-scientists
Charles Darwin	Theory of evolution by natural selection		sci-famous-scientists
Galileo Galilei	Used the telescope to find Jupiter's moons and supported a Sun-centered system		sci-famous-scientists
Nicolaus Copernicus	Proposed that the Earth orbits the Sun		sci-famous-scientists
Johannes Kepler	Laws of planetary motion		sci-famous-scientists
Louis Pasteur	Germ theory, pasteurization and vaccines		sci-famous-scientists
Alexander Fleming	Discovered penicillin in 1928		sci-famous-scientists
Edward Jenner	Created the first smallpox vaccine		sci-famous-scientists
Gregor Mendel	Father of genetics, through pea plant experiments		sci-famous-scientists
Rosalind Franklin	X-ray images that helped reveal DNA's structure		sci-famous-scientists
James Watson and Francis Crick	Proposed the double helix structure of DNA in 1953		sci-famous-scientists
Dmitri Mendeleev	Created the first widely used periodic table		sci-famous-scientists
Antoine Lavoisier	Father of modern chemistry; named oxygen and hydrogen		sci-famous-scientists
John Dalton	Atomic theory of matter		sci-famous-scientists
J. J. Thomson	Discovered the electron		sci-famous-scientists
Ernest Rutherford	Discovered the atomic nucleus		sci-famous-scientists
Niels Bohr	Model of the atom with electron shells		sci-famous-scientists
James Chadwick	Discovered the neutron		sci-famous-scientists
Robert Hooke	Named cells after looking at cork		sci-famous-scientists
Antonie van Leeuwenhoek	First to see bacteria and single-celled life with a microscope		sci-famous-scientists
Robert Boyle	Boyle's law about gases		sci-famous-scientists
Michael Faraday	Electromagnetic induction		sci-famous-scientists
James Clerk Maxwell	Equations of electromagnetism		sci-famous-scientists
Benjamin Franklin	Studied electricity and lightning		sci-famous-scientists
Alessandro Volta	Invented the battery		sci-famous-scientists
Nikola Tesla	Alternating current systems		sci-famous-scientists
Thomas Edison	Practical light bulb and phonograph		sci-famous-scientists
Alexander Graham Bell	Patented the telephone in 1876		sci-famous-scientists
Stephen Hawking	Studied black holes and the universe		sci-famous-scientists
Edwin Hubble	Showed the universe is expanding		sci-famous-scientists
Carl Sagan	Astronomer who made science popular on television		sci-famous-scientists
Jane Goodall	Studied wild chimpanzees in Tanzania		sci-famous-scientists
Dian Fossey	Studied mountain gorillas in Rwanda		sci-famous-scientists
Rachel Carson	Wrote Silent Spring, about pesticides and nature		sci-famous-scientists
Jacques Cousteau	Ocean explorer who co-invented the aqualung		sci-famous-scientists
Sylvia Earle	Oceanographer and deep-sea explorer		sci-famous-scientists
Mae Jemison	Doctor and first African American woman in space		sci-famous-scientists
Katherine Johnson	NASA mathematician who calculated orbits for early space flights		sci-famous-scientists
Ada Lovelace	Wrote an early computer program in the 1840s		sci-famous-scientists
Charles Babbage	Designed an early mechanical computer		sci-famous-scientists
Alan Turing	Pioneer of computer science and codebreaker		sci-famous-scientists
Grace Hopper	Computer pioneer who helped create early programming languages		sci-famous-scientists
George Washington Carver	Agricultural scientist who promoted peanuts and crop rotation		sci-famous-scientists
Archimedes	Ancient Greek who studied levers and buoyancy		sci-famous-scientists
Aristotle	Greek thinker who classified living things		sci-famous-scientists
Hippocrates	Ancient Greek physician called the Father of Medicine		sci-famous-scientists
Euclid	Ancient Greek mathematician known for geometry		sci-famous-scientists
Eratosthenes	Ancient Greek who measured the Earth's size		sci-famous-scientists
Ptolemy	Ancient astronomer who put Earth at the center		sci-famous-scientists
Carl Linnaeus	Created the two-part naming system for species		sci-famous-scientists
Alfred Wegener	Proposed continental drift		sci-famous-scientists
Wilhelm Roentgen	Discovered X-rays in 1895		sci-famous-scientists
Enrico Fermi	Built the first nuclear reactor in 1942		sci-famous-scientists
Max Planck	Founder of quantum theory		sci-famous-scientists
Richard Feynman	Physicist known for quantum electrodynamics and teaching		sci-famous-scientists
Lise Meitner	Helped explain nuclear fission		sci-famous-scientists
Chien-Shiung Wu	Physicist whose experiment changed ideas about particle physics		sci-famous-scientists
Percy Julian	Chemist who made medicines from plants		sci-famous-scientists
Elizabeth Blackwell	First woman to earn a medical degree in the United States		sci-famous-scientists
Florence Nightingale	Nurse who improved hospitals and used statistics		sci-famous-scientists
Clara Barton	Founded the American Red Cross		sci-famous-scientists
Jonas Salk	Developed the first successful polio vaccine		sci-famous-scientists
Barbara McClintock	Discovered jumping genes in corn		sci-famous-scientists
Tu Youyou	Discovered a malaria treatment, won a Nobel Prize in 2015		sci-famous-scientists
Jennifer Doudna	Co-developed the CRISPR gene-editing method		sci-famous-scientists
Light bulb (practical)	Thomas Edison, 1879		sci-inventions
Telephone	Alexander Graham Bell, patented 1876		sci-inventions
Airplane (first powered flight)	Wilbur and Orville Wright, 1903		sci-inventions
Printing press with movable type in Europe	Johannes Gutenberg, about 1440		sci-inventions
Steam engine (improved)	James Watt, 1700s		sci-inventions
Cotton gin	Eli Whitney, 1793		sci-inventions
Telegraph	Samuel Morse and others, 1830s-40s		sci-inventions
Radio	Guglielmo Marconi and others, 1890s		sci-inventions
Television (early electronic)	Philo Farnsworth and others, 1920s		sci-inventions
World Wide Web	Tim Berners-Lee, 1989		sci-inventions
First programmable computer concept	Charles Babbage's Analytical Engine, 1830s		sci-inventions
Vaccine for smallpox	Edward Jenner, 1796		sci-inventions
Polio vaccine	Jonas Salk, 1955		sci-inventions
Penicillin	Alexander Fleming, 1928		sci-inventions
Battery	Alessandro Volta, 1800		sci-inventions
Dynamite	Alfred Nobel, 1867		sci-inventions
Safety pin	Walter Hunt, 1849		sci-inventions
Sewing machine (practical)	Elias Howe, 1846		sci-inventions
Telescope (first used for astronomy)	Galileo, 1609		sci-inventions
Microscope (early compound)	Zacharias Janssen and others, late 1500s		sci-inventions
Thermometer (mercury)	Daniel Fahrenheit, 1714		sci-inventions
Barometer	Evangelista Torricelli, 1643		sci-inventions
Pendulum clock	Christiaan Huygens, 1656		sci-inventions
Lightning rod	Benjamin Franklin, 1750s		sci-inventions
Bifocal glasses	Benjamin Franklin		sci-inventions
Reaper	Cyrus McCormick, 1830s		sci-inventions
Elevator with safety brake	Elisha Otis, 1850s		sci-inventions
Jet engine	Frank Whittle and Hans von Ohain, 1930s		sci-inventions
Transistor	Bardeen, Brattain and Shockley, 1947		sci-inventions
Integrated circuit	Jack Kilby and Robert Noyce, late 1950s		sci-inventions
Personal computer revolution	1970s and 1980s, with machines such as the Apple II		sci-inventions
Mobile phone (first handheld call)	Martin Cooper, 1973		sci-inventions
Laser	Theodore Maiman built the first working laser, 1960		sci-inventions
Satellite (first)	Sputnik 1, 1957		sci-inventions
Automobile (gasoline)	Karl Benz, 1885		sci-inventions
Model T assembly line cars	Henry Ford, 1908		sci-inventions
Bicycle with pedals	Developed in the 1860s		sci-inventions
Paper	Invented in China, about 105 CE		sci-inventions
Printing (woodblock)	Developed in China long before Europe		sci-inventions
Compass	Invented in China		sci-inventions
Gunpowder	Invented in China		sci-inventions
Wheel	Invented in Mesopotamia about 3500 BCE		sci-inventions
Plow	Early farming tool invented thousands of years ago		sci-inventions
Zipper	Whitcomb Judson, 1893, improved by Gideon Sundback		sci-inventions
Velcro	George de Mestral, 1941		sci-inventions
Post-it note	Spencer Silver and Art Fry, 1970s		sci-inventions
Microwave oven	Percy Spencer, 1940s		sci-inventions
Crayons	Crayola introduced them in 1903		sci-inventions
Bakelite plastic	Leo Baekeland, 1907		sci-inventions
Nylon	Wallace Carothers at DuPont, 1935		sci-inventions
Braille	Louis Braille, 1824		sci-inventions
Stethoscope	Rene Laennec, 1816		sci-inventions
Pasteurization	Louis Pasteur, 1860s		sci-inventions
X-ray machine	Based on Wilhelm Roentgen's discovery, 1895		sci-inventions
Insulin discovery	Banting and Best, 1921		sci-inventions
Pacemaker	Developed in the 1950s		sci-inventions
MRI scanner	Developed in the 1970s		sci-inventions
Hot air balloon	Montgolfier brothers, 1783		sci-inventions
Parachute (modern)	Developed by Andre-Jacques Garnerin, 1797		sci-inventions
Rocket (liquid-fueled)	Robert Goddard, 1926		sci-inventions
Space Shuttle	NASA, first launch 1981		sci-inventions
Internet's ancestor	ARPANET, 1969		sci-inventions
Email	Ray Tomlinson, 1971		sci-inventions
GPS	Developed by the US in the 1970s-90s		sci-inventions
Electric motor (early)	Michael Faraday and others, 1820s-30s		sci-inventions
Dynamo generator	Faraday's principle; used widely by 1870s		sci-inventions
Alternating current system	Nikola Tesla and George Westinghouse		sci-inventions
Phonograph	Thomas Edison, 1877		sci-inventions
Motion picture camera	Lumiere brothers and Edison's team, 1890s		sci-inventions
Photography (early)	Louis Daguerre, daguerreotype 1839		sci-inventions
Aqualung (scuba)	Jacques Cousteau and Emile Gagnan, 1943		sci-inventions
3D printing	Developed in the 1980s		sci-inventions
LEGO brick (modern)	Godtfred Kirk Christiansen, 1958		sci-inventions
Scientific method	A set of steps scientists use to answer questions		sci-scientific-method
Observation	Using your senses or tools to notice something		sci-scientific-method
Question	What you want to find out		sci-scientific-method
Research	Learning what is already known about a topic		sci-scientific-method
Hypothesis	A testable prediction or possible answer to a question		sci-scientific-method
Prediction	A statement of what you expect to happen		sci-scientific-method
Experiment	A fair test to check a hypothesis		sci-scientific-method
Variable	Something that can change in an experiment		sci-scientific-method
Independent variable	The thing you change on purpose		sci-scientific-method
Dependent variable	The thing you measure as the result		sci-scientific-method
Controlled variable (constant)	A factor kept the same in every trial		sci-scientific-method
Control group	The group that doesn't get the change, used for comparison		sci-scientific-method
Experimental group	The group that gets the change being tested		sci-scientific-method
Data	Information collected during an experiment		sci-scientific-method
Quantitative data	Data in numbers		sci-scientific-method
Qualitative data	Data in descriptions, such as color or smell		sci-scientific-method
Analysis	Looking carefully at data to find patterns		sci-scientific-method
Conclusion	What the results show about the hypothesis		sci-scientific-method
Trial	One run of an experiment		sci-scientific-method
Repeated trials	Doing the test again to make results more reliable		sci-scientific-method
Sample size	The number of items or subjects tested		sci-scientific-method
Bias	An unfair influence on results		sci-scientific-method
Fair test	A test in which only one variable changes		sci-scientific-method
Reproducible	Others can repeat the experiment and get the same results		sci-scientific-method
Peer review	Other experts checking a scientist's work before it is published		sci-scientific-method
Theory	A well-tested explanation supported by lots of evidence		sci-scientific-method
Scientific law	A statement that describes a pattern in nature, often as an equation		sci-scientific-method
Difference between theory and guess	A theory is backed by much evidence; a guess is not		sci-scientific-method
Model	A representation used to explain or predict something		sci-scientific-method
Inference	A conclusion based on evidence and reasoning		sci-scientific-method
Evidence	Facts that support an idea		sci-scientific-method
Anomaly	A result that doesn't fit the pattern		sci-scientific-method
Error	A difference between a measured value and the true value		sci-scientific-method
Accuracy	How close a measurement is to the true value		sci-scientific-method
Precision	How close repeated measurements are to each other		sci-scientific-method
Average (mean)	The sum of values divided by how many there are		sci-scientific-method
Median	The middle value of an ordered list		sci-scientific-method
Mode	The value that appears most often		sci-scientific-method
Range	The difference between the largest and smallest values		sci-scientific-method
Line graph	Best for showing change over time		sci-scientific-method
Bar graph	Best for comparing categories		sci-scientific-method
Pie chart	Shows parts of a whole		sci-scientific-method
Scatter plot	Shows how two variables relate		sci-scientific-method
Title of a graph	Tells what the graph is about		sci-scientific-method
Axis labels	Say what is measured and the units		sci-scientific-method
Lab report	A written account of an experiment		sci-scientific-method
Materials list	Tells what you need for an experiment		sci-scientific-method
Procedure	The steps followed in an experiment		sci-scientific-method
Safety first	Follow safety rules in every experiment		sci-scientific-method
Metric system	The measurement system scientists use worldwide		sci-scientific-method
Science fair	A contest where students show their experiments		sci-scientific-method
Why change only one variable?	So you know what caused the result		sci-scientific-method
Hypothesis format	If I do this, then that will happen, because...		sci-scientific-method
Correlation	Two things changing together		sci-scientific-method
Causation	One thing causing another		sci-scientific-method
Does correlation prove causation?	No		sci-scientific-method
Placebo	A harmless pill with no medicine, used for comparison in tests		sci-scientific-method
Double-blind test	Neither the subjects nor the testers know who gets the real treatment		sci-scientific-method
Pseudoscience	Ideas that look like science but aren't tested properly		sci-scientific-method
Skepticism	Asking for evidence before believing a claim		sci-scientific-method
Falsifiable	Able to be proven wrong by evidence		sci-scientific-method
kilo-	1,000 times (k)		sci-si-units-prefixes
hecto-	100 times (h)		sci-si-units-prefixes
deka-	10 times (da)		sci-si-units-prefixes
deci-	one tenth (d)		sci-si-units-prefixes
centi-	one hundredth (c)		sci-si-units-prefixes
milli-	one thousandth (m)		sci-si-units-prefixes
micro-	one millionth (the Greek letter mu)		sci-si-units-prefixes
nano-	one billionth (n)		sci-si-units-prefixes
pico-	one trillionth (p)		sci-si-units-prefixes
femto-	10 to the negative 15 (f)		sci-si-units-prefixes
mega-	1,000,000 times (M)		sci-si-units-prefixes
giga-	1,000,000,000 times (G)		sci-si-units-prefixes
tera-	one trillion times (T)		sci-si-units-prefixes
peta-	10 to the 15th (P)		sci-si-units-prefixes
exa-	10 to the 18th (E)		sci-si-units-prefixes
yotta-	10 to the 24th (Y)		sci-si-units-prefixes
yocto-	10 to the negative 24th (y)		sci-si-units-prefixes
How many millimeters in a centimeter?	10		sci-si-units-prefixes
How many centimeters in a meter?	100		sci-si-units-prefixes
How many meters in a kilometer?	1,000		sci-si-units-prefixes
How many millimeters in a meter?	1,000		sci-si-units-prefixes
How many grams in a kilogram?	1,000		sci-si-units-prefixes
How many milligrams in a gram?	1,000		sci-si-units-prefixes
How many milliliters in a liter?	1,000		sci-si-units-prefixes
How many liters in a kiloliter?	1,000		sci-si-units-prefixes
How many kilobytes in a megabyte (decimal)?	1,000		sci-si-units-prefixes
Base unit of length	Meter		sci-si-units-prefixes
Base unit of mass	Kilogram		sci-si-units-prefixes
Base unit of time	Second		sci-si-units-prefixes
Base unit of volume commonly used	Liter		sci-si-units-prefixes
Base unit of temperature in SI	Kelvin		sci-si-units-prefixes
Base unit of electric current	Ampere		sci-si-units-prefixes
Base unit of amount of substance	Mole		sci-si-units-prefixes
Base unit of luminous intensity	Candela		sci-si-units-prefixes
How many base SI units are there?	Seven		sci-si-units-prefixes
About how long is a meter?	A little over 3 feet (39.4 inches)		sci-si-units-prefixes
About how long is a centimeter?	About the width of a fingernail		sci-si-units-prefixes
About how far is a kilometer?	About 0.6 miles		sci-si-units-prefixes
About how heavy is a kilogram?	About 2.2 pounds		sci-si-units-prefixes
About how heavy is a gram?	About a paper clip		sci-si-units-prefixes
About how much is a liter?	A bit more than a quart		sci-si-units-prefixes
About how much is a milliliter?	About 20 drops of water		sci-si-units-prefixes
What does 1 mL of water weigh?	1 gram		sci-si-units-prefixes
Volume of 1 cubic centimeter	1 milliliter		sci-si-units-prefixes
Volume of 1 cubic decimeter	1 liter		sci-si-units-prefixes
25 mm equals how many cm?	2.5 cm		sci-si-units-prefixes
3 km equals how many m?	3,000 m		sci-si-units-prefixes
2 kg equals how many g?	2,000 g		sci-si-units-prefixes
500 mL equals how many L?	0.5 L		sci-si-units-prefixes
1.5 m equals how many cm?	150 cm		sci-si-units-prefixes
Celsius to Fahrenheit	F = C x 9/5 + 32		sci-si-units-prefixes
Fahrenheit to Celsius	C = (F - 32) x 5/9		sci-si-units-prefixes
Freezing point of water	0 C = 32 F = 273.15 K		sci-si-units-prefixes
Boiling point of water	100 C = 212 F = 373.15 K		sci-si-units-prefixes
Normal body temperature	About 37 C (98.6 F)		sci-si-units-prefixes
Room temperature	About 20-25 C (68-77 F)		sci-si-units-prefixes
Convert Celsius to Kelvin	Add 273.15		sci-si-units-prefixes
Scientific notation for 3,000	3 x 10^3		sci-si-units-prefixes
Scientific notation for 0.002	2 x 10^-3		sci-si-units-prefixes
Meter was once defined as	One ten-millionth of the distance from the equator to the North Pole (1790s idea)		sci-si-units-prefixes
Which countries use the metric system officially?	Almost every country; the US mainly uses customary units in daily life		sci-si-units-prefixes
What does SI stand for?	International System of Units		sci-si-units-prefixes
Mass vs weight units	Mass in kilograms; weight (a force) in newtons		sci-si-units-prefixes
Density of water	1 gram per cubic centimeter		sci-si-units-prefixes
Hectare	10,000 square meters		sci-si-units-prefixes
Metric ton (tonne)	1,000 kilograms		sci-si-units-prefixes
Angstrom	One ten-billionth of a meter, used for atoms		sci-si-units-prefixes
Micron (micrometer)	One millionth of a meter		sci-si-units-prefixes
Nanometer	One billionth of a meter; used for wavelengths of light		sci-si-units-prefixes
Constellation	A pattern of stars that people have named		space-constellations
How many official constellations are there?	88		space-constellations
Zodiac constellations	The 12 constellations the Sun appears to pass through in a year		space-constellations
Ursa Major	The Great Bear; contains the Big Dipper		space-constellations
Ursa Minor	The Little Bear; contains the Little Dipper		space-constellations
Big Dipper	A group of seven stars in Ursa Major shaped like a ladle		space-constellations
Little Dipper	Part of Ursa Minor; its handle ends at Polaris		space-constellations
Polaris	The North Star, near the north celestial pole		space-constellations
How to find Polaris	Follow the two stars at the edge of the Big Dipper's bowl		space-constellations
Orion	The Hunter, with three stars in a row as his belt		space-constellations
Betelgeuse	A red supergiant star marking Orion's shoulder		space-constellations
Rigel	A blue-white supergiant in Orion		space-constellations
Sirius	The brightest star in the night sky, in Canis Major		space-constellations
Canis Major	The Greater Dog		space-constellations
Canis Minor	The Lesser Dog; contains Procyon		space-constellations
Taurus	The Bull; contains the Pleiades and Aldebaran		space-constellations
Pleiades	A bright cluster of stars also called the Seven Sisters		space-constellations
Aldebaran	The orange giant star that forms the eye of Taurus		space-constellations
Gemini	The Twins; has Castor and Pollux		space-constellations
Cancer	The Crab		space-constellations
Leo	The Lion; has bright star Regulus		space-constellations
Virgo	The Maiden; has bright star Spica		space-constellations
Libra	The Scales		space-constellations
Scorpius	The Scorpion; has red star Antares		space-constellations
Sagittarius	The Archer; looks like a teapot and points to the center of the Milky Way		space-constellations
Capricornus	The Sea-Goat		space-constellations
Aquarius	The Water Bearer		space-constellations
Pisces	The Fishes		space-constellations
Aries	The Ram		space-constellations
Cassiopeia	A W-shaped constellation named for a queen		space-constellations
Cepheus	The King in the northern sky		space-constellations
Andromeda	Named for a princess; contains the Andromeda Galaxy		space-constellations
Perseus	The hero in the story of Medusa; has the Perseid meteor shower		space-constellations
Pegasus	The Winged Horse, with the Great Square		space-constellations
Cygnus	The Swan, also called the Northern Cross		space-constellations
Deneb	The bright star at the tail of Cygnus		space-constellations
Lyra	The Lyre; contains bright star Vega		space-constellations
Vega	A bright blue-white star in Lyra		space-constellations
Aquila	The Eagle; contains Altair		space-constellations
Summer Triangle	Vega, Deneb and Altair		space-constellations
Bootes	The Herdsman; contains orange giant Arcturus		space-constellations
Arcturus	A bright orange star, the brightest in the northern sky		space-constellations
Crux	The Southern Cross, seen from the Southern Hemisphere		space-constellations
Centaurus	The Centaur; contains Alpha Centauri		space-constellations
Alpha Centauri	The closest star system to the Sun, about 4.3 light-years away		space-constellations
Proxima Centauri	The closest known star to the Sun		space-constellations
Canopus	The second-brightest star in the night sky, in Carina		space-constellations
Draco	The Dragon, winding between the Dippers		space-constellations
Hercules	A large constellation of the hero		space-constellations
Auriga	The Charioteer; has bright star Capella		space-constellations
Capella	A bright yellow star in Auriga		space-constellations
Lepus	The Hare, below Orion		space-constellations
Hydra	The longest constellation		space-constellations
Crater	The Cup		space-constellations
Corvus	The Crow		space-constellations
Ophiuchus	The Serpent Bearer		space-constellations
Milky Way	Our galaxy; seen as a pale band of light across the sky		space-constellations
Andromeda Galaxy	The nearest large galaxy to the Milky Way, about 2.5 million light-years away		space-constellations
Meteor shower	Many meteors seen as Earth passes through a comet's dust trail		space-constellations
Perseids	A meteor shower in August		space-constellations
Geminids	A meteor shower in December		space-constellations
Leonids	A meteor shower in November		space-constellations
Planet vs star in the sky	Planets shine steadily; stars twinkle		space-constellations
Asterism	A star pattern that is not an official constellation, like the Big Dipper		space-constellations
Light pollution	Artificial light that hides the stars		space-constellations
Dark sky	An area with little light pollution, great for stargazing		space-constellations
First artificial satellite, launched 1957	Sputnik 1 (Soviet Union)		space-missions
First animal in orbit, 1957	Laika the dog, on Sputnik 2		space-missions
First human in space, 1961	Yuri Gagarin		space-missions
First American in space, 1961	Alan Shepard		space-missions
First American to orbit Earth, 1962	John Glenn		space-missions
First woman in space, 1963	Valentina Tereshkova		space-missions
First spacewalk, 1965	Alexei Leonov		space-missions
Project Mercury	NASA's first program to put Americans in space		space-missions
Project Gemini	NASA program of two-person flights that practiced docking and spacewalks		space-missions
Project Apollo	NASA program that landed people on the Moon		space-missions
Apollo 8	First crewed mission to orbit the Moon, 1968		space-missions
Apollo 11	First crewed Moon landing, July 1969		space-missions
First person on the Moon	Neil Armstrong		space-missions
Second person on the Moon	Buzz Aldrin		space-missions
Apollo 11 command module pilot	Michael Collins		space-missions
Armstrong's famous words	That's one small step for man, one giant leap for mankind		space-missions
Apollo 13	1970 mission that returned safely after an oxygen tank failure		space-missions
Apollo 17	The last crewed Moon landing, December 1972		space-missions
Lunar rover	A vehicle astronauts drove on the Moon in later Apollo missions		space-missions
Skylab	The first US space station, launched 1973		space-missions
Salyut	The first space station, launched by the Soviet Union in 1971		space-missions
Mir	A Soviet and Russian space station that orbited from 1986 to 2001		space-missions
International Space Station	A research station orbiting Earth, with crews living aboard since 2000		space-missions
ISS orbit height, about	400 kilometers above Earth		space-missions
Space Shuttle	NASA's reusable spacecraft that flew from 1981 to 2011		space-missions
First Space Shuttle to orbit	Columbia, 1981		space-missions
Space Shuttle orbiters	Columbia, Challenger, Discovery, Atlantis and Endeavour		space-missions
First American woman in space	Sally Ride, 1983		space-missions
First African American in space from the US	Guion Bluford, 1983		space-missions
Mae Jemison	The first African American woman in space, 1992		space-missions
Hubble Space Telescope	Orbiting telescope launched in 1990		space-missions
Who is the Hubble named for?	Astronomer Edwin Hubble		space-missions
Voyager 1	Probe launched in 1977; entered interstellar space in 2012		space-missions
Voyager 2	Probe launched in 1977 that visited Jupiter, Saturn, Uranus and Neptune		space-missions
Pioneer 10	The first spacecraft to fly past Jupiter, in 1973		space-missions
Mariner 4	First spacecraft to photograph Mars up close, 1965		space-missions
Viking 1 and 2	US probes that landed on Mars in 1976		space-missions
Mars Pathfinder	1997 mission that carried the small rover Sojourner		space-missions
Spirit and Opportunity	Twin Mars rovers that landed in 2004		space-missions
Curiosity	A Mars rover that landed in 2012		space-missions
Cassini	A probe that orbited Saturn from 2004 to 2017		space-missions
Huygens	A probe that landed on Saturn's moon Titan in 2005		space-missions
Galileo	A spacecraft that orbited Jupiter from 1995 to 2003		space-missions
Juno	A spacecraft that began orbiting Jupiter in 2016		space-missions
New Horizons	Probe that flew past Pluto in 2015		space-missions
Magellan	A probe that mapped Venus with radar in the early 1990s		space-missions
MESSENGER	The first spacecraft to orbit Mercury, 2011		space-missions
Dawn	A spacecraft that orbited the asteroid Vesta and dwarf planet Ceres		space-missions
Rosetta	European mission that orbited a comet and sent a lander in 2014		space-missions
Kepler	A space telescope that found thousands of planets around other stars		space-missions
Spitzer	An infrared space telescope launched in 2003		space-missions
Chandra	A NASA X-ray space telescope launched in 1999		space-missions
Parker Solar Probe	Spacecraft launched in 2018 to fly close to the Sun		space-missions
OSIRIS-REx	A probe that collected samples from asteroid Bennu in 2020		space-missions
Hayabusa	Japanese probes that returned samples from asteroids		space-missions
Chang'e 4	Chinese lander that touched down on the Moon's far side in 2019		space-missions
Challenger disaster	1986 Space Shuttle accident in which seven crew members died		space-missions
Columbia disaster	2003 Space Shuttle accident that lost its seven crew		space-missions
Crew Dragon	SpaceX capsule that carried NASA astronauts in 2020		space-missions
Sputnik	Russian for fellow traveler or satellite		space-missions
Longest single spaceflight by a woman, 2019-20	Christina Koch, 328 days		space-missions
Cosmonaut	A Russian space traveler		space-missions
Taikonaut	A Chinese space traveler		space-missions
Astronaut	A space traveler from the United States and many other countries		space-missions
Launch pad	The platform a rocket lifts off from		space-missions
Kennedy Space Center	NASA's launch site in Florida		space-missions
Baikonur	The launch site in Kazakhstan used by Russian rockets		space-missions
How many natural satellites does Earth have?	One, the Moon		space-moons-sun-earth
How long does the Moon take to orbit Earth?	About 27 days; phases repeat about every 29.5 days		space-moons-sun-earth
Phases of the Moon	The changing shapes of the lit part of the Moon we see		space-moons-sun-earth
New moon	The Moon is not visible because its lit side faces away		space-moons-sun-earth
Waxing crescent	A growing sliver of the Moon		space-moons-sun-earth
First quarter	Half the Moon is lit, the right half in the Northern Hemisphere		space-moons-sun-earth
Waxing gibbous	More than half lit and growing		space-moons-sun-earth
Full moon	The whole face of the Moon is lit		space-moons-sun-earth
Waning gibbous	More than half lit and shrinking		space-moons-sun-earth
Third (last) quarter	Half the Moon is lit, the left half in the Northern Hemisphere		space-moons-sun-earth
Waning crescent	A shrinking sliver of the Moon		space-moons-sun-earth
Why does the Moon have phases?	We see different amounts of its sunlit half as it orbits Earth		space-moons-sun-earth
Does the Moon make its own light?	No; it reflects sunlight		space-moons-sun-earth
Lunar eclipse	Earth's shadow falls on the Moon		space-moons-sun-earth
Solar eclipse	The Moon passes between the Sun and Earth, blocking sunlight		space-moons-sun-earth
Total solar eclipse	The Moon completely covers the Sun's disk		space-moons-sun-earth
Is it safe to look at a solar eclipse without eye protection?	No; use special eclipse glasses		space-moons-sun-earth
Corona	The Sun's outer atmosphere, seen during a total eclipse		space-moons-sun-earth
Craters on the Moon come from	Impacts of asteroids and meteoroids		space-moons-sun-earth
Maria (lunar seas)	Dark, flat plains of ancient lava on the Moon		space-moons-sun-earth
Who first walked on the Moon?	Neil Armstrong in 1969		space-moons-sun-earth
Which mission landed first humans on the Moon?	Apollo 11		space-moons-sun-earth
How many Apollo missions landed people on the Moon?	Six		space-moons-sun-earth
Gravity on the Moon compared to Earth	About one-sixth		space-moons-sun-earth
Why does the same side of the Moon always face Earth?	It rotates once for each orbit (tidal locking)		space-moons-sun-earth
Moon landing year of the last Apollo mission	1972, Apollo 17		space-moons-sun-earth
Largest moon in the solar system	Ganymede, a moon of Jupiter		space-moons-sun-earth
Galilean moons	Io, Europa, Ganymede and Callisto, found by Galileo in 1610		space-moons-sun-earth
Io	A volcanic moon of Jupiter		space-moons-sun-earth
Europa	An icy moon of Jupiter with an ocean beneath its ice		space-moons-sun-earth
Titan	Saturn's largest moon, with a thick atmosphere and lakes of methane		space-moons-sun-earth
Enceladus	A small icy moon of Saturn that sprays water ice from its south pole		space-moons-sun-earth
Phobos and Deimos	The two small moons of Mars		space-moons-sun-earth
Triton	Neptune's largest moon, which orbits backward		space-moons-sun-earth
Charon	The largest moon of Pluto		space-moons-sun-earth
Miranda	A moon of Uranus with cliffs and grooves		space-moons-sun-earth
Titania	The largest moon of Uranus		space-moons-sun-earth
Callisto	A heavily cratered moon of Jupiter		space-moons-sun-earth
Mimas	A small icy Saturn moon with one huge crater		space-moons-sun-earth
Sun	A star made mostly of hydrogen and helium		space-moons-sun-earth
Sun's age, about	4.6 billion years		space-moons-sun-earth
Sun's surface temperature, about	5,500 degrees Celsius		space-moons-sun-earth
Sun's core temperature, about	15 million degrees Celsius		space-moons-sun-earth
What powers the Sun?	Nuclear fusion of hydrogen into helium		space-moons-sun-earth
How long does sunlight take to reach Earth?	About 8 minutes		space-moons-sun-earth
Sunspot	A cooler, darker area on the Sun's surface		space-moons-sun-earth
Solar flare	A sudden burst of energy from the Sun		space-moons-sun-earth
Solar wind	A stream of charged particles flowing from the Sun		space-moons-sun-earth
Aurora	Glowing lights in the sky from solar particles hitting the atmosphere		space-moons-sun-earth
Photosphere	The visible surface of the Sun		space-moons-sun-earth
Solar system formed from	A cloud of gas and dust about 4.6 billion years ago		space-moons-sun-earth
Earth's rotation period	About 24 hours		space-moons-sun-earth
Earth's orbit period	About 365.25 days		space-moons-sun-earth
Leap year	A year with an extra day, February 29, to fix the calendar		space-moons-sun-earth
Why do we have day and night?	Earth rotates on its axis		space-moons-sun-earth
Summer in the Northern Hemisphere happens when	The Northern Hemisphere tilts toward the Sun		space-moons-sun-earth
Satellite	An object that orbits a planet		space-moons-sun-earth
Tidal force	The Moon's gravity tugging on Earth's oceans		space-moons-sun-earth
Supermoon	A full moon at its closest point to Earth, looking larger		space-moons-sun-earth
Blue moon	The second full moon in one calendar month		space-moons-sun-earth
Harvest moon	The full moon nearest the autumn equinox		space-moons-sun-earth
Which planet is closest to the Sun?	Mercury		space-planets
Second planet from the Sun	Venus		space-planets
Third planet from the Sun	Earth		space-planets
Fourth planet from the Sun	Mars		space-planets
Fifth planet from the Sun	Jupiter		space-planets
Sixth planet from the Sun	Saturn		space-planets
Seventh planet from the Sun	Uranus		space-planets
Eighth planet from the Sun	Neptune		space-planets
How many planets are in our solar system?	Eight		space-planets
Memory trick for planet order	My Very Educated Mother Just Served Us Noodles		space-planets
Inner (terrestrial) planets	Mercury, Venus, Earth and Mars		space-planets
Outer planets	Jupiter, Saturn, Uranus and Neptune		space-planets
Gas giants	Jupiter and Saturn		space-planets
Ice giants	Uranus and Neptune		space-planets
Which is the largest planet?	Jupiter		space-planets
Which is the smallest planet?	Mercury		space-planets
Which planet is the hottest?	Venus		space-planets
Why is Venus so hot?	Its thick carbon dioxide air traps heat		space-planets
Which planet is called the Red Planet?	Mars		space-planets
Why is Mars red?	Iron oxide (rust) on its surface		space-planets
Which planet has famous rings?	Saturn		space-planets
Do other planets have rings?	Yes: Jupiter, Uranus and Neptune have fainter ones		space-planets
Which planet spins on its side?	Uranus		space-planets
Which planet has the Great Red Spot?	Jupiter		space-planets
What is the Great Red Spot?	A giant storm larger than Earth, seen for hundreds of years		space-planets
Which planet has the strongest winds?	Neptune		space-planets
Which planet is furthest from the Sun?	Neptune		space-planets
Which planet has the longest day?	Venus, which spins very slowly		space-planets
Which planet spins backward compared to most?	Venus		space-planets
Which planets have no moons?	Mercury and Venus		space-planets
How many moons does Earth have?	One		space-planets
Which planet has the tallest volcano in the solar system?	Mars, Olympus Mons		space-planets
What is the largest canyon in the solar system?	Valles Marineris on Mars		space-planets
Which planet is less dense than water?	Saturn		space-planets
What is Mercury's year length?	About 88 Earth days		space-planets
How long is Earth's year?	About 365 days		space-planets
How long is Mars's year?	About 687 Earth days		space-planets
How long is Jupiter's year?	About 12 Earth years		space-planets
How long is Saturn's year?	About 29 Earth years		space-planets
How long is Uranus's year?	About 84 Earth years		space-planets
How long is Neptune's year?	About 165 Earth years		space-planets
What are Saturn's rings made of?	Pieces of ice and rock		space-planets
What is Jupiter mostly made of?	Hydrogen and helium		space-planets
What gas gives Uranus and Neptune a blue color?	Methane		space-planets
Which planet is the only one with liquid water on its surface?	Earth		space-planets
What does Earth's atmosphere contain mostly?	Nitrogen and oxygen		space-planets
What does Mars's atmosphere contain mostly?	Carbon dioxide		space-planets
Which planet was discovered with a telescope in 1781?	Uranus		space-planets
Who discovered Uranus?	William Herschel		space-planets
Which planet was found by math predictions in 1846?	Neptune		space-planets
Dwarf planet	A round body orbiting the Sun that hasn't cleared its orbit		space-planets
Name the five officially recognized dwarf planets	Ceres, Pluto, Haumea, Makemake and Eris		space-planets
When was Pluto reclassified as a dwarf planet?	2006		space-planets
Who discovered Pluto in 1930?	Clyde Tombaugh		space-planets
Asteroid belt	A region between Mars and Jupiter filled with rocky bodies		space-planets
Kuiper belt	A region beyond Neptune with icy bodies and dwarf planets		space-planets
Oort cloud	A far-off sphere of icy bodies thought to surround the solar system		space-planets
Comet	An icy body that grows a glowing tail near the Sun		space-planets
Asteroid	A rocky body orbiting the Sun, smaller than a planet		space-planets
Meteoroid	A small piece of rock or metal in space		space-planets
Meteor	The streak of light when a meteoroid burns in the atmosphere		space-planets
Meteorite	A piece of space rock that lands on the ground		space-planets
Sun	The star at the center of our solar system		space-planets
Orbit	The path an object takes around another		space-planets
Astronomical unit	The average distance from Earth to the Sun, about 150 million kilometers		space-planets
Gravity on Mars compared to Earth	About 38 percent		space-planets
Star	A huge ball of hot gas that makes its own light by fusion		space-stars-universe
Nebula	A cloud of gas and dust in space		space-stars-universe
Protostar	A young star still forming inside a nebula		space-stars-universe
Main sequence	The long stage when a star fuses hydrogen into helium		space-stars-universe
Red giant	A swollen, cool star near the end of its life		space-stars-universe
White dwarf	The small hot core left after a medium star ends		space-stars-universe
Planetary nebula	A glowing shell of gas thrown off by a dying star		space-stars-universe
Supernova	The explosion of a massive star at the end of its life		space-stars-universe
Neutron star	The super-dense core left by some supernovae		space-stars-universe
Pulsar	A spinning neutron star that sends out beams of radiation		space-stars-universe
Black hole	A region where gravity is so strong that not even light can escape		space-stars-universe
Event horizon	The boundary around a black hole beyond which nothing returns		space-stars-universe
Red dwarf	A small, cool, long-lived star		space-stars-universe
Supergiant	A very large, luminous star		space-stars-universe
Binary star	Two stars orbiting each other		space-stars-universe
Variable star	A star whose brightness changes		space-stars-universe
Nova	A white dwarf suddenly brightening by pulling in gas		space-stars-universe
Star color and temperature	Blue stars are hottest; red stars are coolest		space-stars-universe
Spectral classes from hot to cool	O, B, A, F, G, K, M		space-stars-universe
Spectral class of the Sun	G		space-stars-universe
Luminosity	The total amount of light a star gives off		space-stars-universe
Apparent magnitude	How bright a star looks from Earth		space-stars-universe
Absolute magnitude	How bright a star would look from a standard distance		space-stars-universe
Hertzsprung-Russell diagram	A graph plotting star brightness against temperature		space-stars-universe
Light-year	The distance light travels in one year, about 9.5 trillion kilometers		space-stars-universe
Parallax	The apparent shift of a nearby star against the background as Earth moves		space-stars-universe
Galaxy	A huge collection of stars, gas and dust held together by gravity		space-stars-universe
Milky Way	Our home galaxy, a spiral with a central bar		space-stars-universe
Spiral galaxy	A galaxy with arms curling out from the center		space-stars-universe
Elliptical galaxy	A smooth oval-shaped galaxy		space-stars-universe
Irregular galaxy	A galaxy with no regular shape		space-stars-universe
Galaxy cluster	A group of many galaxies bound by gravity		space-stars-universe
Local Group	The cluster of galaxies that includes the Milky Way		space-stars-universe
Large Magellanic Cloud	A small galaxy that orbits the Milky Way		space-stars-universe
Quasar	An extremely bright center of a distant galaxy powered by a black hole		space-stars-universe
Dark matter	Unseen matter that adds gravity to galaxies		space-stars-universe
Dark energy	A mysterious force that speeds up the expansion of the universe		space-stars-universe
Big Bang theory	The universe began extremely hot and dense about 13.8 billion years ago		space-stars-universe
Expanding universe	Space is stretching, carrying galaxies apart		space-stars-universe
Redshift	Light from receding objects stretches toward red		space-stars-universe
Who found that galaxies move away from us in 1929?	Edwin Hubble		space-stars-universe
Cosmic microwave background	The faint glow left from the early universe		space-stars-universe
Observable universe	The part of the universe we can see from Earth		space-stars-universe
Exoplanet	A planet orbiting a star other than the Sun		space-stars-universe
Habitable zone	The region around a star where liquid water could exist on a planet		space-stars-universe
Telescope	An instrument that gathers light to see faraway objects		space-stars-universe
Refracting telescope	A telescope that uses lenses		space-stars-universe
Reflecting telescope	A telescope that uses mirrors		space-stars-universe
Radio telescope	A dish that collects radio waves from space		space-stars-universe
Spectrum of starlight	Shows what elements a star contains		space-stars-universe
Astronomy	The study of space and everything in it		space-stars-universe
Astrophysics	The branch of astronomy using physics to explain objects in space		space-stars-universe
Cosmology	The study of the origin and structure of the universe		space-stars-universe
Who proposed the Sun-centered solar system in 1543?	Nicolaus Copernicus		space-stars-universe
Who first used a telescope to study the sky in 1609?	Galileo Galilei		space-stars-universe
Who described the laws of planetary motion?	Johannes Kepler		space-stars-universe
Which star is closest to Earth?	The Sun		space-stars-universe
Which star is the closest after the Sun?	Proxima Centauri		space-stars-universe
Star formation location	Inside dense nebulae		space-stars-universe
Chandrasekhar limit	The maximum mass of a white dwarf, about 1.4 solar masses		space-stars-universe
Solar mass	A unit equal to the mass of the Sun		space-stars-universe
Gravitational waves	Ripples in space-time first detected in 2015		space-stars-universe
First image of a black hole shadow, released	2019, in the galaxy M87		space-stars-universe