In honor of #WorldElephantDay we’re making Elephant Toothpaste! This is a fun STEM activity that the kids love to do because of the foamy, exploding reaction.
‼️Do not ingest! Elephant toothpaste is not real toothpaste and is not made for consumption ‼️
Materials Needed:
- Large, empty plastic bottle
- Dry yeast (found in the baking section of the grocery store)
- Warm water
- Liquid dish soap
- 3% hydrogen peroxide
- Measuring cups
- Spoons
- Large tub or tray to catch the foam (or an area that can tolerate spills)
- Liquid food coloring (optional)
- Different-shaped bottles or glasses (optional)
Steps:
- Measure 1/2 cup of hydrogen peroxide, and carefully pour it into the bottle
- Add a big squirt of dish soap into the bottle, and swirl gently to mix
- If you want to make your foam a single color, add a few drops of food coloring directly into the hydrogen peroxide, and swirl the bottle gently to mix. If you want to give your foam stripes like some kinds of toothpaste, put the drops along the inside rim of the bottle’s mouth. Let them drip down the inside of the bottle, but do not mix
- In a measuring cup mix together one tablespoon of yeast and three tablespoons of warm water. Stir for about 30 seconds
- Pour the yeast mixture into the bottle then quickly step back, and watch your reaction go!
Observations and Results:
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!