Soapy Solutions

(You can do this with your friends or family--or even by yourself.)

Did you know that there are millions of microbes on your hands? Most are harmless, but some may be disease-causing germs. Washing your hands is one of the best ways to prevent the spread of infections.

When was the last time you washed your hands? Was it a quick splash under cold water? Did you use soap? What have you done since you washed? Have you eaten, put your fingers in your mouth, or touched someone else? Do you think your hands were clean?

Try this experiment and you'll discover the most effective way to remove bacteria from your hands.

What You'll Need
cooking oil
cinnamon
measuring spoons
a sink

What To Do
1. Rub 1 tablespoon of cooking oil all over your hands until completely coated. Sprinkle 1 teaspoon of cinnamon on your hands and rub it around until it's evenly distributed. The cinnamon will be like bacteria. It's all over!

2. Then wash your hands, but try different methods. (If you're doing this with friends, each of you can try a different way and you can compare your success with each other.)

Each time rub your hands briskly for 20 seconds and record the results. Look for the amount of cinnamon (pretend bacteria) that remains after each method.
#1 Wash you hands with cold water and no soap.
#2 Wash your hands with warm water and no soap.
#3 Wash your hands with warm water and soap.

Did you get them clean without soap? Did warm water help? When you wash your hands in real life, soap lifts off millions of microbes and rinses them away.

Does it matter how much time you spend washing them?

3. Try it again. This time use warm water and soap, but change the length of time:
#1 Rub for 5 seconds
#2 Rub for 10 seconds
#3 Rub for 20 seconds

4. What did you learn?
Which method removed the most cinnamon (or bacteria)?
Which method removed the least?
How long does it take to get the bacteria washed off?
Why does the warm water help? Soap? Rubbing?

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