Make an easy lava lamp with a few ingredients.
- 600ml bottle with lid
- Vegetable oil
- Food colouring
- Alka-Seltzer tablets
- ¼ fill bottle with water
- Add 5 drops of food colouring
- Fill the rest of the bottle with oil – leaving 2cm space from the top
- Add 1 Alka-Seltzer tablet
- Watch the reaction
- Once the bubbles have stopped put the lid back on and keep for next time.