Materials List:

1. Film canisters
2. One jar per color of paint
3. Paint
4. Water
5. Alka-Seltzer tablets
6. Paper or index cards

Set-Up

Mix together 50% paint and 50% water for each color you want to use, then store the paint-water mixture in jars. Spread out the paper for your rockets.

We recommend taking this activity outside, since it’s very messy! Paint will fly everywhere when you set off your rocket, and it will stain materials like cement.

Try This

1. Add a spoonful of paint-water mixture to each film canister.

2. Drop a fizzing tablet into the film canister.

3. Quickly cap the canister and flip it upside down.

4. Step back and wait for lift-off!

5. The rocket should pop open and fly into the air, leaving a paint splatter behind.

Go Further

When you mix the tablets with water, a chemical reaction occurs with the citric acid and sodium bicarbonate contained in the tablet and the water. The chemical reaction creates bubbles of carbon dioxide. The carbon dioxide gas builds up in the closed film canister. Since the lid is the weakest point of the canister, it pops off and releases all of the gas from the canister’s end. This causes the canister to fly into the air.

The paint rocket is an example of Newton’s Third Law of Motion, which states that “every action has an equal and opposite reaction.” The gas rushing out of one end of the canister (the action) causes the rocket to move in the opposite direction (the reaction).

Wrap-Up

Thanks for reading Science and Play Connections, the Montana Science Center blog! We hope to see you in person at the Montana Science Center. Check out https://montanasciencecenter.org/ for information on our exhibits, programs, camps, and other offerings. Have a great day!