Why You Need to Use Soap (a Germs Simulation Experiment)

I'm not sure my oldest son uses soap every time he showers. And I've seen our youngest son put soap on one hand and then instead of rubbing them together, stick the soapy hand immediately under the running water. Hopefully this simple, yet fun, experiment has convinced them of the merits of soap.
The experiment is meant to simulate how soap helps to get rid of germs.

What You Need plate (or saucer) with a raised edge water ground black pepper dishwashing liquid (we used Ms. Meyer's)
What to Do Pour water onto the plate. You should use enough water to cover the whole bottom of the plate.
Sprinkle several pinches of ground black pepper onto the water. Explain that these specks of peppers represent germs.

Now squirt a dot of dishwashing liquid onto one of your index fingers. Rub it all around, completely covering the tip of the finger.
Lastly, put your soap-covered finger into the middle of the peppered water.

Be amazed. The soap seems to repel the pepper (aka the "germs").

Why it Works This activity was discovered on Fantastic Fun and Learning. As explained by Shaunna, "When soap is added to the water it lowers the surface tension of the water causing the water molecules on the surface to scatter or pull away from the point where you added the soap."

What to Read You can't go wrong with a Magic School Bus Book. We have rediscovered our love for all things Frizzle this summer. This book complemented the activity beautifully!