At home for 5-11 11-14
- Level Elementary
What you need
- Two small plastic bottles
- Kitchen paper
- Sticky tape
- Drinking water at room temperature
- A breezy day (on a still day, you’ll just have to wait a bit longer)
- Fill both bottles with room-temperature drinking water
- Wrap one of the bottles in two layers of kitchen paper, holding it in place with sticky tape. Wet the paper with water
- Put both bottles outside in a breezy spot and leave them for 25 minutes before drinking
Results and Explanation
Water in the kitchen paper evaporates, taking heat from the water in the bottle and cooling it. Any breeze speeds up the evaporation and hence the cooling.
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.