Exploding bags with baking soda and vinegar-science lesson. They take off like rockets!
Gummy bear experiment
TEABAG ROCKET: Amaze your kids! How it works: “Everyone knows that hot air rises and this experiment demonstrates that idea as well as the principles of convection currents. As the tea bag burns, hot air is being created, as well as a thermal, or convection current, under the bag. When the tea bag burns down into a small enough ball of ashes, the convection current causes it shoot up in the air.” [Quoted directly from Steve Spangler Science.]