“You can imagine that it’s like trying to go over a hill,” Dr. Morris said. “It takes some energy to walk up the incline and you’ll sweat a little bit, but once you get past the top, you can keep going really easily.”

Adding a catalyst, such as potassium iodide, essentially bulldozes a path through the hill. The substance helps hydrogen peroxide form less stable compounds that can stroll through the newly opened path to the other side. Basically the catalyst helps produce water and oxygen, while releasing some heat.

Store-bought yeast also contains a chemical called catalase that can help break down hydrogen peroxide, although its effects are not as dramatic as potassium iodide. This means that adding yeast to a solution of hydrogen peroxide will break down the peroxide. The oxygen gas that’s released will form bubbles and try to escape.

Mixing in a little bit of dish soap in the reaction will create enough surface tension that oxygen bubbles will get trapped, Dr. Morris said.

“It helps you visualize what’s happening by creating foam.”

Here’s the recipe, adapted from Science Buddies, so you can try it out for yourself.

Materials

Empty plastic bottle

3 percent hydrogen peroxide solution, available at nearly any drug or grocery store

One packet of active yeast found in the baking section of the grocery store

Liquid dish soap

Warm water

Food coloring (to make the reaction look pretty)

Preparation

Set up in a sink or go outdoors. You will want to do the experiment in a location where it will be easy to clean up all the foam afterward.

Stand away from the bottle once you add all the chemicals for the reaction. Hydrogen peroxide can irritate the skin and discolor clothing, even in low concentrations. (In chemical experiments using concentrated hydrogen peroxide like the one Ms. Schrier performed, scientists wear safety glasses and personal protective equipment.)

Procedure

Carefully pour ½ cup hydrogen peroxide into the plastic bottle and add a big squirt of dish soap. Swirl gently to mix.

Add 2 to 3 drops of food coloring to the solution. (If you want to give your foam stripes, put the drops on the edge of the bottle’s mouth, but do not mix them in.)

In a separate container, mix 1 tablespoon of yeast and 3 tablespoons of warm water. Wait about 5 minutes for the yeast to activate.