Have you ever been mesmerized watching a lava lamp? This groovy decoration was a huge fad in the 1960s. When turned on, heat causes colored globules to float up and sink over and over again but never mix into a new substance. The two liquids inside are insoluble with one another and have different densities (although ones that use electricity have much closer densities than the one used in this experiment).

You can make your own version of a lava lamp at home using a few simple ingredients!

Learning Time

Prep Time 2-3 mins

Age Range 6+

Keywords: experiment, density, polarity

Materials List

• Clean plastic bottle
• Water
• Vegetable Oil
• Food Coloring
• Fizzy Tablets (ex. Alka Seltzer)
  

Directions

1. Take a clean plastic bottle and fill about one quarter of the way with water.

2. Add oil in to bottle until it is nearly full, saving a little bit of room.

3. Once water and oil have fully separated, add a few drops of food coloring.

4. Break one fizzy tablet in half and drop it in to your bottle.

5. Observe the colored bubbles sink and float!

Take it further:

Try this experiment with different oils, different amounts of water, or even different amount of fizz tablets to check out the differences!