Discover the reason we wash our hands with both soap and water and why it is important to get germs off our hands. This is a quick and easy STEM experiment!

Did you know that germs are tiny organisms that we can’t see without a microscope? Even though germs are very small they can make us sick! Germs live on services like door handles, on the playground, on the floor, and our HANDS! Because we use our hands to eat, pick up things, and shake hands with others,  it is important to wash our hands throughout the day to prevent sickness. In this experiment, we will learn what happens to germs when we wash our hands with just water versus when we wash our hands with both soap and water.


  • Medium size bowl
  • Small size bowl
  • Water
  • Pepper
  • Liquid soap

1.      First fill the medium size bowl halfway with water.

2.      Then pour a small amount of liquid soap (2 tablespoons) into the small size bowl.

3.      Next, shake lots of pepper flakes into the medium size bowl. Think of the pepper as little are germs

4.      Dip a finger into the medium size bowl.

Let’s Observe:

What happens to the germs (pepper)?  Nothing!   Did the germs (pepper) stay on the finger? Yes! Did anything happen to the “germs”? No!

5.  Now stick the finger into the bowl of soap and then into the bowl of peppery water.

Let’s Observe:

 What happens to the germs(pepper)? It moves away from the finger!  Are there  (pepper pieces) “germs” left on the finger? No!


This experiment shows us that soap removes germs from our hands and teaches us that rinsing hands with water doesn’t work well! Germs don’t like soap which is why it is important to wash hands regularly with soap and water to stay happy and healthy. Click here for a Germ Coloring Sheet.