1 balloon 1 empty 16 oz plastic soda bottle 3 tablespoons baking soda half cup vinegar plastic funnel

1. Pour 1/2 cup of vinegar into an empty plastic soda bottle and set aside.
2. Use a funnel to dump about 3 tablespoons of baking soda into a deflated balloon.
3. Carefully stretch the neck of the balloon and wrap it around the opening of the bottle, letting the baking soda settle inside the hanging balloon.
4. Use your fingers to hold the balloon on the neck of the bottle, making sure there are no air leaks. Then lift the balloon up so the baking soda falls into the vinegar.

Whomp. Your balloon inflates itself! It is cheap, it is fast, it is easy. And if the balloon pops off the top of the bottle, then it ís a little messy, too.

This classic combination of baking soda and vinegar produces a chemical reaction (which is not as scary as it sounds). The vinegar is an acid. The baking soda is a base, the opposite of an acid. When theyíre mixed, the chemicals rearrange to form a salt and a gas. The gas that inflates the balloon is carbon dioxide, the same stuff we exhale when we breathe.