Part of our kindergarten science curriculum requires us to teach the difference between a solid, liquid, and gas. This is a really simple and engaging experiment I found for helping students recognize a solid, liquid, and gas.
plastic water bottle
Fill the water bottle a little more than half way with water.
Explain to students that the tablet and the water bottle are both solids and the water is a liquid.
Break an Alka-Seltzer tablet in half and drop it in the water.
Observe the reaction between the tablet and the water. Point out the bubbles that are popping at the surface of the water and explain that the reaction created carbon dioxide bubbles (a gas).
Have students draw their observations.
Next, tell students you are going to repeat the activity using more Alka-Seltzer tablets and covering the top of the bottle with a balloon. Have students write and share their predictions of what they think will happen to the balloon.
Add 1-2 Alka-Seltzer tablets to the water and quickly cover the top of the bottle with the balloon. The trapped gas from the carbon dioxide bubbles will cause the balloon to inflate! Here is a time-lapse video:
We decided to find out what would happen if we added even more Alka-Seltzer to the water.
The additional Alka-Seltzer created more gas which got trapped in the balloon and made it inflate even more.
Have students draw what actually happened and write what they learned.
Alka-Seltzer Snow Experiment – Here is another fun and engaging experiment that uses Alka-Seltzer and snow to teach students about the chemical reaction between an acid and a base.