Get Elephant Toothpaste Worksheet

To make it a true experiment, you can try to answer these questions: Does the amount of yeast change the amount of foam produced? Will the experiment work as well if you add the dry yeast without mixing it with water? Does the size of the bottle affect the amount of foam produced?

0:00 0:51 And add a squirt of dish soap. Take four spoonfuls of water. And one spoonful of yeast and mix it upMoreAnd add a squirt of dish soap. Take four spoonfuls of water. And one spoonful of yeast and mix it up pour the yeast solution into your container.

The sodium iodide reacts with the hydrogen peroxide (H2O2) by removing an oxygen atom. This essentially produces water and oxygen gas (H2O + O2). The oxygen gas produced gets trapped in the soap which produces the big ball of foam.

The independent variable is the temperature of the water used. The dependent variable is the foam produced in the reaction. The controlled variable are the amounts of yeast, hydrogen peroxide, dish washing liquid, water, and food coloring that is used.

Central Focus: In this activity, students will observe a chemical change by combining a yeast mixture with hydrogen peroxide and dish soap. The resulting foam (“elephant's toothpaste”) demonstrates a chemical reaction that can “explode” in student engagement!

The hypothesis is that by mixing hydrogen peroxide, yeast, and dish soap together, a reaction will occur that produces a lot of foam.

Elementary students may ask questions around how each ingredient "works" in creating elephant toothpaste. Does adding more yeast make it bigger or faster or hotter? Why is the yeast in the water? Will it work if you don't put the yeast in water?

The Science: The yeast contains an enzyme called Catalase that breaks down hydrogen peroxide (H2O2) into oxygen gas and water. The oxygen gas gets trapped by the soap, and you get a large foamy solution that squirts out of the top of the bottle!