Did you know that the same stuff that makes fizzy candy go POP can also make a rocket go POW? The fizz in fizzy candy comes from teeny-tiny bubbles of carbon dioxide gas, trapped inside the sugar. As it turns out, carbon dioxide gas is super easy to make. You just need baking soda and citric acid mixed in water. That kicks off a chemical reaction which creates… carbon dioxide! So, if that reaction happens inside of a bottle, the carbon dioxide gas builds up… and builds up… until the pressure for