Phase Change
Properties of Matter

Liquid Strength

Enrichment Activity for 5-11 11-14

What you need

  • About 5 kg of cornflour
  • Water
  • A large bowl


  1. Find a place where it’s OK to get messy. Mix some of the cornflour and water together into a thick paste. Keep mixing until it’s ankle-deep
  2. Jump very suddenly onto the mixture. Try jumping on and off, or standing still

Results and Explanation

You shouldn't sink if you jump suddenly, but if you stand on it, you'll gradually sink.
The mixture is a special type of liquid that gets less runny when you stir it and turns solid if you hit it hard. The force of the impact makes the starch in the cornflour clump together so it supports your weight at first.

Phase Change
can be analysed using the quantity Energy
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