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Soap vs. Germs: How Does Soap Remove Germs?

Soap vs. Germs: How Does Soap Remove Germs?

Ages 6-125-10 minutesEasy Difficulty

About This Activity

Learn how soap works to remove germs by breaking down grease and oil, demonstrated with a simple pepper and water experiment.

Materials Needed

  • A bowl of water
  • Ground black pepper
  • Liquid soap

Safety Notes

  • Avoid getting soap in your eyes.
  • Wash hands after the experiment.

Instructions

  1. Pour water into a bowl.
  2. Sprinkle ground black pepper on the surface of the water. Imagine the pepper represents germs.
  3. Dip your finger in the water without soap and observe that the pepper stays in place.
  4. Now, dip your finger in liquid soap, then touch the water again.
  5. Watch as the pepper spreads away from your finger, showing how soap helps remove germs.

How It Works

Soap molecules have two sides: one side attracts water, and the other attracts grease and oil. When you use soap, it grabs onto the grease and germs, allowing water to wash them away. In this experiment, the soap disrupts the surface tension of the water, causing the pepper to scatter.

Tips for Success

  • Try using different types of soap to see if they work the same way.
  • Experiment with other small particles like cinnamon instead of pepper.
  • Make handwashing fun by singing a song while scrubbing for 20 seconds.