Before You Start
Get everything you need
🧰 Materials
Clear glass or jar (2–3 for comparison)
Soda water / carbonated water
Raisins (a handful)
Grape
Corn kernel
Small pasta piece
Cause-and-Effect Sheet printable
Pencil
⚠️ Safety First!
This one is safe to do on your own — just be careful not to splash!
All materials are food-safe
Keep soda water away from eyes — the carbonation can sting
Pour slowly to avoid splashing
Do not drink the water after the experiment
What You'll Do
🍇
You're going to drop raisins into a glass of fizzy soda water and watch something amazing happen — they'll sink, then suddenly rise back up, over and over, like they're dancing!
This happens because tiny gas bubbles in the soda water stick to the bumpy surface of the raisins. The bubbles act like little balloons, lifting the raisin up to the surface. When the bubbles pop, the raisin loses its lift and sinks back down — ready to catch more bubbles and rise again!
Then you'll test other small objects — a grape, a corn kernel, a piece of pasta — to discover which ones make the best dancers, and which ones just sit at the bottom the whole time.
Dancing Raisins Dance-Off
Follow along carefully
Pour the Soda Water
🥤
Pour soda water into a clear glass — fill it about 3/4 full.
Tip: The fresher the bottle, the more bubbles you'll get!
2
Make a Prediction
✏️
Before dropping anything in — make your prediction! Write or draw which objects you think will dance.
Tip: There's no wrong prediction — scientists guess before they test!
3
Drop In the Raisins
🍇
Drop in 5–6 raisins. Watch closely — how long before the first one rises?
Tip: Watch the bottom of the glass — that's where the bubbles start forming!
4
Track One Raisin
👀
Try to track one single raisin with your eyes. Count how many times it goes up and down in 60 seconds.
Tip: Pick the raisin closest to you so it's easy to follow!
5
Test More Objects
🍝
After 5 minutes of observing raisins, add a grape, a corn kernel, and a small pasta shape.
Tip: Drop them in one at a time so you can watch each one separately!
6
Record Your Results
📋
Record on your Cause-and-Effect Sheet: which ones danced? Which sank and stayed? Which floated on top?
Tip: Compare your results to your prediction — were you right?
Try It Different Ways
🎨
Little Kids (5-6)
Focus on just the raisins and counting how many times one raisin goes up and down. Use simple words like "up" and "down" to describe what's happening.
🔬
Big Kids (7-8)
Test all 4 objects (raisin, grape, corn kernel, pasta) and record results on the Cause-and-Effect Sheet, comparing which danced longest.
🧪
Challenge!
Try the same objects in plain still water instead of soda water. Do they still dance? Explain why or why not in your own words.
What's Happening?
🧒 Kid Explanation
Soda water is full of tiny invisible gas bubbles called carbon dioxide. When you drop a raisin in, its wrinkly, bumpy skin gives the bubbles lots of little spots to grab onto and stick.
Once enough bubbles stick to the raisin, they act like a bunch of tiny balloons all working together, and they lift the raisin all the way up to the top! But once it reaches the surface, the bubbles pop and float away — so the raisin loses its lift and sinks back down to start all over again.
🔬 Grown-Up Explanation
This activity demonstrates buoyancy and the relationship between an object's effective density and the surrounding fluid. Carbon dioxide gas, dissolved in the soda water under pressure, nucleates and forms bubbles preferentially on irregular surfaces like a raisin's wrinkled skin. As bubbles accumulate, they increase the raisin's overall volume without significantly increasing its mass — lowering its effective density below that of the surrounding liquid, which causes it to rise. At the surface, the bubbles burst and release into the air, returning the raisin to its original density, and it sinks again. This cycle repeats until the soda water loses enough dissolved CO2.
This directly supports NGSS K-PS2-1, investigating how pushes and pulls affect the motion of an object.