Magic Pepper!


Objective

This experiment teaches about surface tension.

Supplies

  • Black pepper (ground not kernels)
  • Water
  • Plate/Dish/Bowl
  • Dish Soap

Procedures

  1. Pour water into a plate or bowl
  2. Shake the pepper on top of the water until a thin layer covers the top
  3. Dip your finger into the pepper and water… what happens?
  4. Now, put a drop of dishwasher soap onto your finger and dip your finger in the plate… what happens now?

Take-away

  • Surface tension is the force that causes molecules on the surface of a liquid to be pushed together and form a layer.

  • In this experiment, the soap breaks the surface tension that makes the pepper float on top of the water. 

  • This causes the water molecules to move away from the soap, and pepper molecules go with them.