Making a lava lamp

You have to agree … lava lamps are pretty groovy!

What you’ll need:

– Alka-Seltzer tablets

– Water

– A clear plastic bottle

– Food colouring

– Vegetable oil


1. Quarter-fill your bottle with water.

2. Pour in the oil until it reaches the top.

3. Add food colouring.

4. Cut the Alka-Seltzer tablets into small pieces and drop them into the bottle. The more you put in, the more bubbles you’ll get.

What’s the science?

Oil and water don’t mix – they remain separated. The Alka-Seltzer tablets release carbon dioxide gas that rises to the top and takes some of the coloured water with it.

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