Lava Lamp

Materials: Plastic bottle with cap, Vegetable oil, 1 Alka Seltzer tablet, Food colouring, and Water

Procedure:

1. Fill the plastic bottle ¾ full with vegetable oil
2. Add water to the neck of the bottle, leaving a little space between the water line and the top of the container
3. Add 10 drops of food colouring
4. Break the tablet into small pieces and put it in the bottle
5. When the bubbling stops replace the bottle cap
6. Move the bottle back and forth and see the reaction