Phase Change
Properties of Matter

Instant Snow

Enrichment Activity for 5-11 11-14

What you need

  • Filtered water
  • Plastic water bottles
  • Freezer


  1. Fill two plastic water bottles with filtered water and leave them on their sides in the freezer.
  2. After two to three hours take one bottle out to test it. Slam it on the counter once and see if anything changes.

Results and Explanation

You should see crystals of ice form at the top of the bottle and flurry downwards quickly.

Supercooled water is water that is liquid below its freezing point. When you slam the bottle it causes ice crystals to move and others to grow in a chain reaction.

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.

Phase Change
can be analysed using the quantity Energy
2023 IOP Awards

Teachers of Physics Awards

Recognising and celebrating outstanding contributions to the field of physics education.

Learn more