Science
What is Surface tension?
Surface tension is the 'skin-like' force at the surface of a liquid, caused by its molecules pulling on each other. It's why water forms droplets, why some insects can walk on water, and why a gently placed paperclip can float.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains surface tension.
Key things to understand
- 1It's the cohesive force at a liquid's surface.
- 2Molecules pull on each other, tightening the surface.
- 3It lets water form droplets and beads up.
- 4It supports light objects and water-walking insects.
Frequently asked questions
- What is surface tension?
- The force at a liquid's surface from its molecules attracting each other, making it behave like a thin skin.
- Why can some insects walk on water?
- Surface tension creates a film strong enough to support their light weight without breaking.
- How does soap affect surface tension?
- Soap lowers water's surface tension, which is part of how it helps water wet and clean surfaces.