How to Make Elephant Toothpaste
How To Make Elephant Toothpaste
Create a giant foaming reaction, and use science to wow your friends with this classic activity. With just a few ingredients you can make something that looks like foamy toothpaste being squeezed from a tube—but so big that it looks almost fit for an elephant!
You might be familiar with hydrogen peroxide as an antiseptic used to clean cuts and scrapes, which it does by killing bacteria. But what is it? It is a liquid made from hydrogen atoms and oxygen atoms (its chemical formula is H2O2). It is available in different strengths, or concentrations. You usually find it in a 3 percent concentration (although higher concentrations are available, they are more dangerous and must be handled carefully). It also breaks down when exposed to light, which is why it usually comes in dark brown bottles.
When hydrogen peroxide breaks down, it turns into oxygen (O2) and water (H2O). Normally this breakdown happens very slowly. But you can make that reaction happen faster! How? By adding a catalyst. Yeast is an organism that contains a special chemical called catalase that can act as a catalyst to help break down hydrogen peroxide. Catalase is present in almost all living things that are exposed to oxygen, and it helps them break down naturally occurring hydrogen peroxide.
This means that if you mix yeast with hydrogen peroxide, the hydrogen peroxide will rapidly break down into water and oxygen gas. The oxygen gas forms bubbles. These bubbles would usually escape from the liquid and pop quickly. But adding a little dish soap provides additional surface tension, allowing the bubbles to get trapped and creating lots of foam. This foam looks like a giant squeeze of toothpaste—almost big enough for an elephant!
- Empty plastic bottle
- Dry yeast (found in the baking section of the grocery store)
- Warm water
- Liquid dish soap
- 3% hydrogen peroxide
- Measuring cups
- Measuring spoons
- Safety glasses
- Large tub or tray to catch the foam
- Location for the activity that can tolerate spills (of hydrogen peroxide as well as possibly food coloring), such as a kitchen or bathroom—or an outdoor location
- Liquid food coloring (optional)
- Different-shaped bottles or glasses (optional)
- Put on your safety glasses to do this activity because hydrogen peroxide can irritate your eyes. (Note: although the product of this activity resembles toothpaste, it is not toothpaste, so do not attempt to use it!)
- Gather your materials in the location where you plan to do your activity. Place your plastic bottle on the tray or tub so that it is easy to clean up all the foam.