Balloon Inside a Bottle

An experiment for Physics 101. Boil 1TBSP of water inside a glass bottle. (The stove works best). Boil the water until it is almost gone. The water evaporates into the bottle, creating steam. Once the water is almost all evaporated, take the bottle off the stove and place onto a dry surface. (Remember to wear oven mitts!). Quickly place a balloon on top of the bottle neck. And watch it get sucked in!