At home for 5-11 11-14
What you need
- A cheap battery-driven clock
- A freezer
- A small plastic box
- Tissue paper or cotton wool
- Take the clock and put it in the box. Pack it in with tissue paper or cotton wool to keep it dry. Don't use your best clock, just in case it gets damaged!
- Put the box in the freezer and leave it for about an hour
- Take the clock out - is it still working?
Results and Explanation
Put it in your living room and wait a day or two – it should start working again eventually.
Batteries use chemical reactions to make a current flow. It flows with much more difficulty inside a battery at freezing temperatures, so that the battery doesn’t work, but it usually returns to normal when it’s warmed up.
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.