We had lots of fun in Senior Infants making lava lamps using small plastic bottles, water, oil, food colouring and effervescent tablets. Have a look at the photos here.

First, we filled a quarter of the bottle with water.

Next, we filled the rest of the bottle with oil. We already knew from a previous experiment that the oil would float on the water because it is lighter.

The next step was to add some food colouring which sank down through the oil and coloured the water.

Lastly, we dropped in the effervescent tablet. It went through the oil and when it mixed with the water it began to fizz (a chemical reaction which created cabon dioxide gas). This caused colourful bubbles to rush up and down through the oil creating a lava lamp effect.