Materials: Plastic bottle with cap, Vegetable oil, 1 Alka Seltzer tablet, Food colouring, and Water
Procedure:
- Fill the plastic bottle ¾ full with vegetable oil
- Add water to the neck of the bottle, leaving a little space between the water line and the top of the container
- Add 10 drops of food colouring
- Break the tablet into small pieces and put it in the bottle
- When the bubbling stops replace the bottle cap
- Move the bottle back and forth and see the reaction