Top 10 science fair projects for 4th graders
Every project on this list is one of Peabody's own, free, with the hypothesis, steps, results table and board plan on its page.
How it's ordered: Projects that fit 4th grade, the ones built most squarely for 4th first (their grade range centred nearest 4th), then the fewest days.
The ten projects
- 🍎 What keeps a cut apple from going brown? (ours): 2nd–6th grade · 1 day of testing · about $1. When an apple is cut, its cells break open and a substance inside them meets the air and turns brown.
- 🍬 Which liquid dissolves a hard candy fastest? (ours): 2nd–6th grade · 1 day of testing · about $2. Hard candy is mostly sugar, and sugar dissolves in water: the water pulls tiny bits of sugar away one at a time.
- 🧊 What melts ice fastest: salt, sugar or sand? (ours): 2nd–6th grade · 1 day of testing · free. Salt dissolves into the thin skin of water on the ice and makes it harder for that water to freeze again, so the ice keeps melting.
- 💧 Does ice melt faster in water or in air? (ours): 2nd–6th grade · 1 day of testing · free. Ice melts when heat flows into it.
- 🧊 Which makes ice water colder: salt or sugar? (ours): 2nd–6th grade · 1 day of testing · free. Anything that dissolves in water lowers the temperature at which it freezes, so sugar and salt can both make ice water colder than plain ice water.
- 📄 How many paper layers block a flashlight? (ours): 2nd–6th grade · 1 day of testing · free. Paper stops light by soaking some of it up and bouncing some in many directions, and each layer takes a bit more.
- 🥛 Does whole milk swirl farther than skim milk? (ours): 2nd–6th grade · 1 day of testing · about $2. Milk is mostly water with tiny drops of fat floating in it, and soap grabs onto fat.
- 🖊️ How many colours hide in a marker's ink? (ours): 2nd–6th grade · 1 day of testing · about $2. Many marker inks are mixtures of different coloured dyes.
- 📄 Which paper pulls water up the highest? (ours): 2nd–6th grade · 1 day of testing · about $1. Paper is made of tiny fibres with gaps between them.
- 🪙 Which kitchen liquid cleans an old penny best? (ours): 2nd–6th grade · 1 day of testing · about $1. A dull penny is covered with a thin brown layer, where the copper has joined with the air.
- science fair projects for 2nd graders
- science fair projects for 7th and 8th graders
- science fair projects you can finish in a weekend
- science fair projects that cost nothing
- science fair projects about plants and weather
- free science fair project sites
- mistakes on a science fair board
- things science fair judges ask
- science fair rules every school shares
- free graph makers for a science fair
- free science fair judging tools
- science fair projects for kindergarten
- science fair board ideas
- science fair kits, honestly priced (with the free swap for each)
👨👩👧 For grown-ups and teachers: how much to help, the safety rules, and running a school fair. Science fair v0.16.1 · Checked .