Book 1, Question 103
Why Does Soap Clean Things? Tiny Molecules With Two Ends!
Water alone slides right off grease, so how does soap help? A soap molecule has one end that loves water and another that loves grease. The grease-loving tails tuck in around the oil while the water-loving heads face outward, which gives water a handle so the dirt rinses away. The page says one drop of soap can surround millions of grease droplets. Compare an oily plate with water only and with water plus one drop of soap.
From the book
Page from A Million Whys Book 1
More fun facts
- People have been making cleaning products for nearly 5,000 years.
- Soap is made from fats and oils.
- Some germs, like the virus that causes COVID-19, wear a fatty outer coat. Soap pries that coat open so the germ falls apart.
- Soap molecules then trap the tiny broken bits, and water washes them away.
- Doctors suggest scrubbing every part of your hands with soap for at least 20 seconds.
- Warm or cold water both work for handwashing, so you don't need hot water.
- Regular soap works fine. You don't need special antibacterial soap.
Sources: National Geographic, KidsHealth (Nemours), Cleveland Clinic, BBC
Questions kids ask
How long should I wash my hands?
Doctors suggest scrubbing every part of your hands with soap for at least 20 seconds.
Do I need hot water to wash my hands?
No. Warm or cold water works fine.