Phase Change
Properties of Matter
Sew an Ice Cube
At home for 11-14 14-16
- Activity time 15 mins
What you need
- Salt
- A cup of cold water
- 20cm of sewing thread
- An ice cube
Instructions
- Float the ice cube in the cup of water
- Lay one end of the thread (or a loop) on top of the ice cube
- Sprinkle a little salt over the top
- Wait one minute then gently lift the thread
Results and Explanation
Salt lowers the melting point of water so the ice melts. But the water quickly refreezes, trapping the string in place.
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.