Science Week lesson plan: Liquid layers (KS2)

Science Week lesson plan: Liquid layers

Demonstrate how liquids can float on top of one another in a density column.


  • Golden syrup
  • Washing up liquid
  • Water
  • Vegetable oil
  • Surgical spirit
  • Pipettes
  • Clear plastic cup
  • Small objects such as a coin, dried pea or bean, grape, pen lid and a dice


  1. Pour golden syrup into the cup so it is about 1.5 cm deep.
  2. Use a pipette to add approximately the same volume of washing up liquid to the cup, on top of the golden syrup.
  3. Use a clean pipette to gently add the same volume of water to the top of the washing up liquid.
  4. Use a clean pipette to gently add the same volume of vegetable oil to the top of the water.
  5. Finally, add a layer of surgical spirit.
  6. If any of the layers have mixed, give them time to settle.
  7. Drop the small objects into the cup, one-by-one, and observe what happens.


Density is defined as how much ‘stuff’ is packed into a particular area. A denser object weighs more than the same amount of a less dense object. Liquids that have a higher density, such as syrup, will sink below liquids with a lower density, such as water and oil. Solid objects also range in their densities. They sink into the liquid layers, resting at different levels depending on their density.


  • What would happen if you mixed the liquids together?
  • What other combinations of liquids could you try?
  • What would happen if you added the liquids in a different order?

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Published by

Dr Fran

Dr Fran Barnes is Cornerstones' expert in primary science. Fran is a molecular and cell biologist with a passion for hands-on, practical science in the classroom. She writes our Love to Investigate series and the science topics in our curriculum.

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