Super Scientist Lenwood taught us how to make a rocket propel. He brought in Alka-seltzer tablets cut in half, a bottle of water, and a film canister made into a rocket. He placed a little water in the canister with half of Alka-seltzer tablet. He put the lid tight and placed it on the ground. We watched the rocket propel 3 feet in the air. He did this a couple of times. The rocket propels when the water and the alka-seltzer combine. The pressure from the carbon dioxide forces the top to pop off so the gas can escape. Then the rocket is propelled upward. They loved seeing this experiment.