Warwickshire County Council
Newton's Bruises

June's Investigation of the Month

Lava experimentYou need:

  • a clear glass or jar
  • water
  • vegetable oil
  • salt

How to do it:

  1. Put water into the jar until it is just over half full.
  2. Pour vegetable oil into the jar. The oil floats on water.
  3. Take a spoonful of salt tip it into the jar quickly all in one go. It sinks through the oil, and down through the water taking some of the oil with it.
  4. Keep looking as the oil globules begin to slowly rise through the water.

lava lamp in actionWhat's happening: The salt drags some of the oil down through the water, some of the salt begins to dissolve, this frees some of the oil and as oil floats on the water, oil being less dense than water, the oil globules rise back to the surface of the water.

Try adding raisins and make them dance.

Try using colour to make a two colour lava lamp.