When the can is heated, the air goes out of the can and
it fills with water vapor. When the can is allowed to cool
with the cap on, the water vapor condenses and air wants
to get back in. But since air can’t, the pressure inside the
can is less than outside the can, and the air outside pushes
on the can and it crinkles. (Fall 1997)
As the can cooled, the molecules of water as a gas would
liquify. As there began to be less molecules of gas pushing
out from within the can, the molecules of gas in the air
outside the can would begin to push in on the can more
frequently than the molecules inside, causing them to
push the sides of the can in. (Fall 1997)
When the can was heated the water turned to water vapor
filling the can with gas. When the can is taken off and
capped to cool, the vapor molecules begin to condense
into (liquid) water reducing the pressure inside the can
which causes the can to be crushed by the atmospheric
pressure trying to equal out the two pressures.
(Fall 1997)