Give your kids some hands on science lessons with a Halloween twist and make a self-inflating ghost this year! All you need is an empty plastic water bottle, baking soda, vinegar, white balloons, and a black marker. First, add enough vinegar to the bottle to fill it up about a quarter to halfway full. Then take the black marker and draw eyes and a mouth on a white balloon. Put one tablespoon of baking soda into the balloon. Attach the balloon to the end of the water bottle. Once the balloon is secure, lift the balloon, allowing the baking soda to fall into the vinegar. Immediately a chemical reaction takes place between the vinegar and the baking soda. Carbon dioxide is released in the process, and it quickly rises to the top. This inflates the balloon, and your "ghost" has formed!