Why Does Pepper Run Away From a Drop of Dish Soap?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why does pepper run away from a drop of dish soap?

The Big Idea

Pepper runs away from soap because soap breaks the tight skin on the top of water! Water's surface is held tight by surface tension. Soap loosens that grip, so the tighter water pulls the pepper away.

Water Skin

Step one: water has a skin. Water molecules pull on each other, and at the surface they pull sideways and downward, like a stretchy sheet. That is called surface tension, and it can hold up light pepper flakes.

Soap Arrives

Step two: soap touches the water. Soap gets in between the water molecules, so the pull gets weaker where the soap lands. That spot becomes a weak patch in the skin.

Pull Away

Step three: the tight water wins. The water farther away is still pulling strongly, so it tugs the surface, and the pepper, away from the soap. The pepper isn't scared, it is just being pulled along!

A Closer Look

Let's take a closer look! Start with a bowl of still water. Pepper floats on the tight skin of the water. A soapy fingertip weakens the skin in one spot. And the pepper gets pulled to the edges.

Quick Facts

Quick facts! Some bugs, called water striders, walk on water thanks to surface tension. Soap is also why bubbles can form and stay round. Dish soap cleans grease by grabbing both oil and water. Soap is for hands and dishes, so never taste it, and wash your hands after.

Think Like a Scientist

Now, think like a scientist! Sprinkle pepper on a bowl of water. Touch the surface with a soapy fingertip. Watch the pepper rush away. Then wash your hands, and never taste the soapy water.

Outro

Soap breaks water's tight skin, and the pepper zooms away. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!