Just imagine if elephants brushed their teeth… Weird, right? A pea-sized amount of toothpaste would be more like a basketball-sized amount. Plus, the brush would be HUGE!
Well, they call this experiment “Elephant’s Toothpaste” because that’s exactly what it looks like: giant toothpaste. Try this chemistry project out with some friends!
Note: The Elephant’s Toothpaste will overflow. Cover your work surface!
*Get an Adult* Hydrogen peroxide can irritate skin and eyes. Ask an adult to handle hydrogen peroxide. Use safety goggles.
- Clean, clear 16-ounce plastic soda or water bottle (Amazon link: Water Bottle)
- 1/2 cup 6% hydrogen peroxide (sold at beauty supply stores or hair salons as a “20-volume” liquid – meaning it is 6% hydrogen peroxide. Amazon link: 20 Volume Hydrogen Peroxide)
- 1 tablespoon (or one packet) of dry yeast (Amazon link: Active Dry Yeast)
- 3 tablespoons warm water
- Liquid dish-washing soap (Amazon link: Dawn Dish Soap)
- Food coloring (optional. Amazon link: Food Coloring)
- Small cup (Amazon link: Small Plastic Cups)
- Safety goggles (Amazon link: Safety Goggles)
- Tray, newspaper, or similar items to cover work surface (Amazon link: Metal Tray)
- Funnel (Amazon link: Plastic Funnel)
- Have an adult pour the hydrogen peroxide into the soda or water bottle. You can use a funnel for this; just make sure to wash it afterwards.
- Add about 8 drops of food coloring into the bottle.
- Put 1 tablespoon of liquid dish-washing soap into the bottle and swirl the bottle.
- Combine the warm water and the yeast together in a separate cup and mix for approximately 30 seconds.
- Clean the funnel from step 1 if you haven’t done so already.
- Get ready for some action! Use the funnel to pour the yeast-water mixture into the bottle and watch the foam!
- Use more or less yeast. Does this change how much foam is produced?
- Add the dry yeast without water. Does the experiment work as well?
- If you use a differently sized bottle, does this affect the amount of foam produced?
Each bubble of the Elephant’s Toothpaste foam is filled with oxygen. The yeast acted as a catalyst to remove oxygen from the hydrogen peroxide. It did this very fast and created lots of tiny bubbles. As you probably noticed, the bottle got warm. When you mixed the two substances, this created an exothermic reaction, a reaction that creates heat. The foam is made of water, oxygen, and soap, which makes for an easy clean-up. Just clean up with a sponge or any absorbent cloth and pour the remaining liquid down the drain. Even though this project is called “Elephant’s Toothpaste,” don’t put the foam in your mouth!