I did a first grade class presentation on air and air pressure today. The kids loved watching a balloon fill up with gas from Pop Rocks dropped in a soda bottle. I did the Mentos and Coke experiment, with one Mento in a small Coke bottle, since I didn't want an 18-foot eruption indoors. The only problem? The kids didn't want me to stop.
Combining Pop Rocks with Sprite inflates a balloon