This is a really fun do at home activity. With just a few items from your kitchen you can create a bubbling version of a lava lamp. To get started gather up some vegetable oil, water, food coloring, a plastic bottle and some effervescing (the bubbling kind) antacid tablets.

Start by cleaning out the bottle and filling it with about 2 inches of water. Now pour in the vegetable oil to nearly the top. In order to color your lava, you will need to add several drops of food coloring. Notice that the food coloring does not mix or color the oil as the drops sink.

Materials:

• Plastic bottle (any size)
• Vegetable Oil
• Water
• Effervescing antacid tablet
• Food Coloring

What to do:

1. Fill the plastic bottle with 2 inches of water.
2. Fill the rest of the way with vegetable oil.
3. Put in 5 or 6 drops of food coloring.
4. Drop in an effervescing antacid tablet and you just made your very own lava lamp.
5. Try putting a flashlight under the bottle see what the lava lamp looks like now!

What is the Science?
Oil will not mix with water it is an example of a hydrophobic molecule. The term hydrophobic literally means water fearing from the Greek language hydros “water” and phobos “fear”. Food coloring is a hydrophilic molecule. The term hydrophilic literally means water loving from the Greek language hydros “water” and philic “friendship”. The food coloring has the ability to mix or transiently bond with the water (H2O) through hydrogen bonding. When you place the effervescing antacid tablet into the bottle it will dissolve in the water and form bubbles of carbon dioxide gas. The gas rises and takes some of the colored water along with it to the surface of the oil. When all of the gas has escaped out of the top of the bottle the water droplet falls back to the bottom of the bottle.