How to Make a Lava Lamp

We are big fans of cool science experiments, especially when they are simple to set up!

This lava lamp science project doesn’t make a real lava lamp, but it is a great way to talk about density while watching your homemade lava lamp swirl. You know you’ve always wanted to know how to make a lava lamp!

bottle (check your recycling bin)
water
oil (use whatever is cheapest)
food coloring
Alka-Seltzer tablets (affiliate link)

Fill the bottle 1/4 to 1/3 of the way full with water and then add oil. Fill it almost all the way too the top and add the food coloring.

This part is almost as cool as the lava lamp itself. The food coloring is more dense than the oil so falls right through the oil and mixes with the water. This is a great time to talk about the density of different liquids.

Now it’s time for the action! Break up the alka-seltzer tablet and add it to the top of the bottle. The fizzing action creates lots of little bubbles that temporarily swirl the colored water throughout the oil. It’s so much fun to watch.