surface tension

/ˌsʌrfəs ˌtɛnʃən/

Surface tension is a chemical phenomenon that happens at the surface of a liquid where the liquid becomes denser than the rest.

The surface is the outside of something: the visible or outer part, like your skin. Tension is an action that makes something tighter, like if you tense a muscle. So surface tension is something that happens to liquids when the surface becomes more tense or solid than the rest of the liquid, due to intermolecular forces. A bug can walk across a pond because of surface tension.

Definitions of surface tension

1. noun

   a phenomenon at the surface of a liquid caused by intermolecular forces
   types:

   capillarity, capillary action

   a phenomenon associated with surface tension and resulting in the elevation or depression of liquids in capillaries

   interfacial surface tension, interfacial tension

   surface tension at the surface separating two non-miscible liquids

   type of:

   physical phenomenon

   a natural phenomenon involving the physical properties of matter and energy