Pepper and Soap Science Trick
Check out this nifty science trick which you can easily try at home.
This is a great way for kids to learn about water surface tension.
How does it work?
The pepper floats because it does not dissolve in water (it’s hydrophobic), while water molecules like to stick together, so they push the pepper flakes up.
This is what we call water surface tension. It’s the tension cause by water molecules ‘sticking together’ and that helps keep the pepper floating.
The soap breaks the water’s surface tension and the water pulls back to the sides to regain the tension. While doing so, the water drags the pepper flakes along with it.
Here’s what you need –
1. A bowl or a plate
2. A cup of water
3. Ground black pepper
4. Dish soap