🌈 Water temperature and spreading colour: the whole packet

🌈 Water temperature and spreading colour · 2nd–8th grade · 1 day of testing · free · 45 minutes a sitting

My days, if the fair is 14 days away

Count back from your fair day and write in each date. Fewer days than this? The jobs share days, in this order; nothing is skipped.

Dates from my teacher

• My question is due
• Testing starts
• My results table and graph are due
• My board is due

In this packet

1. 🗓️ My project plan
2. 💭 My hypothesis
3. 🧺 Change, measure, keep the same
4. 🪜 My steps
5. 📊 My results
6. 📓 My logbook
7. ✅ My conclusion
8. ✂️ Board titles to cut out
9. 🏅 The judge's questions and my certificate

If I change how warm the water is, then how long one drop of colour takes to spread through the whole cup will ________________, because _____________________________________________

What I think will happen, in my own words:

3 levels × 3 tries at each = 9 tries in all. If anything you keep the same changes, you won't know which change made the difference.

What I need

• 🌈 Food colouring: one dark colour
• 🧊 Cold water from the fridge
• 🚰 Water from the tap: left out for an hour, for room temperature
• ♨️ Hot water from the tap or kettle, for a grown-up to pour: hot from the tap, never boiling
• 🥛 Clear plastic cups, all the same size: 3
• 🥛 A measuring cup
• 🌡️ A thermometer (digital, or the red-liquid kind)
• ⏱️ A stopwatch or a kitchen timer

Be safe: 🔥 Hot · 🧽 A bit messy

1. Pour a cup of fridge-cold water into the first clear cup, and room-temperature water into the second.
2. Grown-up: A grown-up pours a cup of hot water into the third cup.
3. Grown-up: A grown-up measures each cup with the thermometer, and you write the temperatures down.
4. Let the cups sit still for a minute, so the water stops swirling.
5. Add one drop of colour to each cup, one after another, and start the timer.
6. Don't stir or bump them: write down the time when each cup has no clear water left.
7. Grown-up: A grown-up empties the cups and pours fresh hot water for each new try.
8. Do the whole test two more times.
9. Find the mean time for each cup, and draw a line graph with temperature along the bottom.

Write each number in your results table the moment you measure it.

I changed: Water   I measured: how long one drop of colour takes to spread through the whole cup (seconds)

MY GRAPH (a line graph: water along the bottom, seconds up the side)

What I noticed: ______________________________________________

Write something every day you work on it, even the days you only gather things. More days? The three-page logbook prints from peabody.kids/science-fair/templates/logbook.

My hypothesis was ☐ right ☐ partly right ☐ not right.

I know because my numbers show:

What surprised me, or what might have gone wrong (7th and up):

Next time I would test:

Idea: Change a second thing: use half a cup and a whole cup of water at each temperature, and draw a line for each.

1. What made you want to ask this question? Say something like: I wanted to know: does food colouring spread faster in hot water?
2. What did you think would happen, and why? Say something like: I thought changing how warm the water is would change how long one drop of colour takes to spread through the whole cup, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed how warm the water is (Cold from the fridge, Room temperature, Hot, poured by a grown-up) and measured how long one drop of colour takes to spread through the whole cup in seconds.
4. What did you keep the same, and why does that matter? Say something like: I kept the same amount of water in each cup and one drop of the same colour the same, so only how warm the water is was different.
5. How many times did you test it? Say something like: 3 times at each of my 3 levels, and I found the middle number.
6. What did you find out? Show me in your numbers. Say something like: Look at my table: Cold from the fridge and Hot, poured by a grown-up gave different numbers, and here's the pattern.
7. Was your hypothesis right? How do you know? Say something like: My numbers show whether I was right, partly right or not, and I can show you where.
8. Did anything go wrong, or surprise you? Say something like: One try was odd, so I did it again and wrote it in my logbook.
9. If you did it again, what would you change or test next? Say something like: I'd change a second thing: use half a cup and a whole cup of water at each temperature, and draw a line for each.