What you need:
A glass jar, a balloon, a bowl of ice water, a piece of string
What you do:
- Blow up the balloon so that it is just a little too big to go into the jar.
- Tie the end of the balloon with a piece of string so that the air cannot get out.
- Now place the balloon in a bowl of ice water.
- After some time take the balloon out and try to put it into the glass jar.
What you find:
The balloon goes inside the jar.
Why does this happen?
When you put the balloon in the cold water. the air in it gets cooled. The cooled air contracts and so the balloon diminishes in size and is able to go into the jar.
Picture Credit : Google