Pepper on the Run

Send pepper running with this simple surface tension experiment.

What you need

• Pepper
• Dish soap
• A bowl of water

What you do

1. Pour a generous amount of pepper into the bowl of water. Most of it should float on the top.
2. Put a drop of dish soap on your finger and touch the surface of the water. The pepper will scatter to the edges of the bowl!

This is due to surface tension — a property of water that allows it to resist outside forces. Common dish soap decreases water’s surface tension, causing the water in your bowl to spread out and take the pepper with it.