Crushing the can
The hypothesis that an empty soda can having a lower internal pressure will collapse inwards due to the higher exterior water pressure is proven to be true.
When the water in the soda can starts to boil, the air is pushed out (displaced) by the steam from the boiling water. The air space in the can is replaced by the steam. When the can is turned upside down and pushed into the cold water, the steam quickly cools and turns back into water droplets in an instant, creating a vacuum inside the can. The water pressure outside the can immediately starts to push against the walls of the soda can. This causes the walls of the soda can to collapse inwards.
Try to repeat the experiment with different types of metal containers.
Try another experiment by capping an empty plastic bottle tightly and placing it in the freezer.
Atmospheric pressure - http://en.wikipedia.org/wiki/Atmospheric_pressure
Air pressure -http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/circulation/air_pressure_p_1.html
1. Perform the experiment under adult supervision.
2. Be careful, and request assistance if necessary, when handling the stove, and when removing the hot soda can from the stove and placing it in the cold water.