Punching Marshmallows

Experiments

What You Need:

Method:
Conclusion:

Although a marshmallow appears to be solid, it is actually filled with many pockets. These pockets are filled with air, like in a sponge. When you suck the air out of the bottle you are decreasing the pressure inside the bottle, which causes the spongy marshmallow to expand. When you stop sucking on the straw and remove the straw from your mouth the air rushes back into the bottle, increasing the pressure and causing the marshmallow to return to its original size.