Running Pepper

The Action

Watch pepper "run" across the top of the water when soap is added to the water.

Grade Level

Grade 1 - Motion

Grade 2 - Air and Water

Grade 3 - Properties of Matter

Grade 7 - Force and Motion

Grade 9 - Fluids and Pressures


Large Container



Dishwashing Soap


Fill the container three quarters full of water. Sprinkle pepper over the surface of the water so that it is fully covered. Cover one finger with soap and put it in the water in the center of the container. The pepper should shoot out to the sides of the container.


It is important for the students to know that the soap that you put on your finger is safe. It cannot be something that you should not get on your skin, for example, bleach. It would be a good idea to review with children chemical safety and danger signs that are on product labels.


Ensure that the finger is heavily coated with soap.

Science Principle

Water acts like it has a layer of skin on the top of it. The soap breaks that skin and pulls the pepper away to the sides of the glass.

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