We don’t think about it much, but soap and water have an amazing ability to clean skin and wash away dirt and grease. You’ve heard it said that washing with water isn’t enough, but you may not know why that is so. Here’s the scoop. The tail of the soap molecule embeds dirt and grease, and the head pulls it towards water and embeds it in lather until it can be rinsed away. The entire molecule activates when you rub water and soap on your skin.
I’m especially amazed at the powers of the molecule head. It turns out that water doesn’t wet so well on it’s own. It tends to form tight droplets that don’t spread. The molecule head acts as a surfactant. That is, it releases tension on the surface of the water so the water can spread and soak in.