While it won’t look exactly like the lava lamps of the 60s, with just a couple of ingredients you can make the next best thing in the comfort of your own home.
The materials you will need are:
- A tall clear container (a drinking glass or bottle will also work)
- Cooking oil
- Food coloring OR liquid watercolor
- Alka-Seltzer tablets
- A table covering (newspaper, tray, anything that protects your workspace from potential messes)
What you need to do:
Cover your workspace to protect it from potential messes.
Fill up a container about ¾ of the way with vegetable oil.
Fill the rest of the container with water.
Add five or six drops of food coloring OR liquid watercolor.
Have an adult break up an Alka-Seltzer tablet and drop it into the container.
Wait and watch your lava lamp come to life! You may have to wait a few seconds before your mixture starts reacting.
Add more Alka-Seltzer as the reaction slows down.
When you’re finished with this activity, let the water and oil settle. The oil can be poured out slowly and saved for the next time you’d like to do this science experiment.
How does this work?
Because water is denser than oil it sinks to the bottom of your container, while the oil floats just above the water.
The Alka-Seltzer reacts with the water on the bottom of your container to create carbon dioxide gas bubbles. These bubbles react with the water, and this mixture of gas and water becomes less dense than the oil.
That’s why you see the colorful bubbles rising through the layer of oil and up to the surface. Once the gas/water bubbles pop, the gas escapes into the air, and the water within those bubbles becomes denser than the oil and floats back down.