- a plastic bottle
- baking soda
- a balloon
- funnel (to fill the balloon with baking soda)
- We poured about 1 1/4 cups of vinegar into the bottle.
- We filled the balloon (about 3/4 full) with baking soda.
- We attached the balloon to the top of the bottle -- making sure there was a tight seal.
4. We carefully dumped the baking soda into the bottle and watched as the balloon filled with air.