Collapsing Bottle

What you need

• A plastic bottle
• Some hot water

Instructions

1. Very carefully pour a little hot water into the bottle, or ask a grown-up to help
2. Shake the bottle
3. Pour out the water
4. Put the lid on, put the bottle down and wait a few minutes

Results and Explanation

The hot water raises the temperature - the pressure increases and the molecules spread out (some leave the bottle). When the air cools, the pressure is lower than before because there are fewer molecules bouncing around. The air pushing on the outside of the bottle has more pressure, which crushes the bottle.

These experiments have not been specifically safety tested for home use but we believe them to be safe if the instructions are followed. Adult supervision or direction is recommended as appropriate. All experiments are carried out at your own risk.