How Does Soap Make You Clean?

Have you ever wondered why your parents tell you to wash your hands with soap and water?

If we zoomed in really close on a soap molecule, we’d see that it has a round head and long tail—like a balloon. The head of a soap molecule is hydrophilic (hi-druh-FI-luk) and the tail is hydrophobic (hi-druh-FOW-bik). The hydrophilic end is attracted to water molecules while the hydrophobic end is attracted to other molecules like oil.

There are all kinds of substances on our hands—dirt, food, sweat, and oil. Each of these substances is either hydrophilic or hydrophobic. Hydrophilic substances can be dissolved in water while hydrophobic substances cannot.

When you rinse your hands off with just water, the hydrophilic particles are washed off. But particles like oils are hydrophobic, so the water slips right off them. We need a little extra help from soap to remove these things from our hands.

Since soap molecules have both hydrophilic and hydrophobic ends, they trap most of the things that water alone can’t remove. Rubbing your hands together helps the soap molecules better break down and trap all the gunk. After scrubbing for about 20 seconds, rinse the soap suds off, and your hands are clean!

How Does Soap Clean Germs?

Our hands are covered in these tiny organisms (microorganisms), some of which we call germs. In a fallen world, germs can make you sick. Scrubbing with soap and water will wash the germs away with the dirt and oil that covered your hands, win-win!

Do you have a question about God’s Word or his world that you want us to answer? Is there a topic you want to learn more about? Ask your parents to help you submit your question today. Watch for our answer here on the blog or in Kids Answers magazine. We’d love to hear from you!