Making a lava lamp

You will need: a bottle, some water, food colouring or paint, oil, aka seltzer (or a fizzing tablet - we find fizzing vitamins work well).

1. Fill 3/4 of the bottle with vegetable oil.
2. Mix the food colouring/paint with water.
3. Fill the rest of the bottle with the coloured water.
4. Break an alka-seltzer tablet into a few small pieces - we usually cut it into quarters (its a nice opportunity to talk abut whole, half and quarters), and drop them in the flask one at a time.
5. Watch your lava lamp erupt into activity!

If you enjoyed this, you might also like our other activities; making a bug that walks on water, wax crayon and water art, making it rain in a jar, milk marbling and shadow drawing. You can find all 6 pages of activities here.