In this Science Fun activity, kids create a safe chemical reaction that some people like to call elephant toothpaste. We all know elephants don’t actually brush their teeth, but if they did, we bet their toothpaste would look something like this!

Using common household materials, like hydrogen peroxide, liquid dish soap, yeast, water, and food coloring, kids learn what happens when molecules break apart. The yeast causes the molecules in the hydrogen peroxide (H₂O₂) to break down into oxygen gas (O) and water (H₂O). The soapy water captures the oxygen gas in bubbles. And the food coloring, well, that just makes it look pretty!

For older students who are looking to expand upon the chemistry of this experiment, each molecule of hydrogen peroxide has two hydrogen atoms and two oxygen atoms. The yeast acts as a catalyst that decomposes the hydrogen peroxide, liberating the water and the extra oxygen atom. This is an exothermic reaction, which means it releases heat, too. The foam is made up of oxygen gas, which gets trapped in the soapy water. But don’t worry…it’s perfectly safe to handle!

What does the mixture in the bottle look like? Is anything happening? What do you think will happen when you pour the yeast slurry into the bottle? Use the included investigator’s journal to record your predictions and observations.

Download the free Science Fun: Elephant Toothpaste PDF or check out the rest of the science activities.

This activity is part of PTO Today’s Family Science Night kit, a free program that helps PTO and PTA leaders plan a night of hands-on learning and discovery about science at school. The free Family Science Night toolkit includes step-by-step planning guidelines, promotional tools, take-homes, and 20-plus STEM projects for kids. Bring the Family Science Night program to your school.