This lava lamp science experiment will be a big hit with the kids, as they’ll explore how oil reacts with water, plus they’ll get to play with vibrant colours with an eruptive twist!


What you’ll need

  • Vegetable oil
  • Water
  • Food colouring
  • Alka Seltzer tablets


lava lamp experiment



  • To begin, add some food colouring to half a cup of water.
  • Fill a separate tall glass about ¾ full with vegetable oil, then pour in the coloured water leaving about 1-2” from the top. (This is so it doesn’t overflow, so if you’re wary and want to prevent a big cleanup then place the glass onto a tray).
  • Break up some Alka Seltzer tablets into 2 or 3 pieces, then let your kids plop them into the glass to see what happens!


They will notice that the water and oil do not mix and that the oil doesn’t change colour as the food colouring is water soluble, so the glass will be full of colourful blobs. The Alka Seltzer tablets will react with the water to create carbon dioxide bubbles, which will attach to the colourful water blobs and bring them up to the surface. When the bubbles pop, the blobs will fall back to the bottom of the glass. This will create a buzzing lava lamp effect that your little ones will be mesmerised with!

Lava Lamps Experiment

Try different colours or even a mixture of vibrant tones in the same glass. A similar experiment to try involves mixing a tablespoon of white paint with water, then adding it to baby oil and plopping in pieces of Alka Seltzer tablets in to create a mesmerizing blizzard effect in a glass!

For more fun science experiments check out