Create your very own lava lamp using materials found at home in this fun and simple science experiment.

You Will Need:

  1. Vegetable Oil
  2. Water
  3. Food Colouring
  4. Empty Water Bottle
  5. Alka-Seltzer Tablets

The Experiment

  1. Fill the empty water bottle ¾ full with oil
  2. Fill the remaining ¼ of the bottle with water
  3. Wait for the layers of water and oil to separate and settle
  4. Add several drops of food colouring into the bottle which will pass through the oil and colour the water
  5. Break the Alka-Seltzer tablet into 3-4 smaller pieces and drop a piece in. Here come the bubbles!
  6. When the bubbling stops, drop another piece in for more bubbles!

The Science

The oil and water separate and oil stays above the water because it is lighter and less dense. This also occurs because water is a polar molecule and the oil is a nonpolar molecule so they do not mix.

The food colouring has the same density as the water so it sinks through the oil into the water at the bottom of the bottle. 

Once you add the Alka-Seltzer tablet, it sinks into the water, fizzes, and dissolves because the citric acid and baking soda in the tablet react with water, creating sodium citrate and carbon dioxide gas. 

The gas is lighter than the water so it rises to the top in the form of bubbles. Some of the coloured water attaches to the bubbles. The bubbles reach the top and pop as the gas escapes, and the colour sinks back down into the water.

This continues to occur until the Alka-Seltzer finishes reacting and you add more Alka-Seltzer to keep the reaction going.

Want More Epic Experiments?
If you enjoyed this experiment and want to learn more, want more fun, more science, and more epic experiments, enrol now in our science holiday camps and spring term science classes where kids can learn, experiment, explore, and play!