Energy Transferred by Heating
Energy and Thermal Physics

Thirsty Bottle

Enrichment Activity for 5-11 11-14

What you need

  • Glass bottle
  • Plate
  • Hot water
  • Room temperature water


  1. Pour some water onto a plate
  2. Fill the bottle with hot water. The water and the bottle will be hot so you might need to ask a friend to help.
  3. Carefully pour the water away and quickly place the bottle upside down on the plate of water. The water will rise up the bottle.

Results and Explanation

The hot bottle heats the air inside it. Once the air cools it takes up less space. The air pressure inside the bottle becomes less than the air pressure outside. This forces the water up 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.

Limit Less Campaign

Support our manifesto for change

The IOP wants to support young people to fulfil their potential by doing physics. Please sign the manifesto today so that we can show our politicians there is widespread support for improving equity and inclusion across the education sector.

Sign today