So what happened?
The water in the marshmallows was heated up by the microwave. This, in turn, warmed up and softened the sugar in the marshmallows. Energy (heat) from the water molecules also heated up the air bubbles in the marshmallows, making the air bubbles move faster and caused the walls of the marshmallows to expand. When the marshmallows cooled, the air bubbles shrank and the sugar hardened.
EXPLODING FILM CANISTERS
What you’ll need:
sunglasses or safety goggles half a tab of Alka-Seltzer an empty 35-mm film canister with its lid water
How to do it:
Put on your sunglasses on safety goggles, then place the Alka-Seltzer tab in the film canister. Fill the canister halfway up with water. Place the lid oh the canister and toss the canister on the ground, at least ten feet away from where you’re standing. Watch with glee as the whole thing goes flying in the air.
So what happened?
The gas pressure created by the Alka-Seltzer tablet as it dissolved forced the lid off the film canister and sent it flying into the air.
Phineas L. MacGuire . . . Erupts! Page 6