Scientific principle: Chili can float on the water surface because there is surface tension on the surface of water, forming a water film. The surface of pepper is hydrophobic and light, so it will stay on this layer of water. Detergent contains surfactant, which can destroy the surface tension of water and water film, so that pepper can not be carried by water film, so it will disperse.

Tools/raw materials: water, cups, pepper, detergent.

1. Take a clean water cup (it will be more effective).

2. Add more than half a glass of water to the glass.

Sprinkle a layer of pepper on the water.

4. Insert a clean stirring rod, and the pepper has not changed.

5. Put a layer of detergent on the stirring rod and insert it into the pepper. Found that the pepper around the stirring bar ran away.