Surface Tension

A thermodynamic property of a liquid interface defined as energy per unit area (or equivalently force per unit length) that resists increases in surface area and arises from cohesive forces among molecules at the interface.

The reversible work per unit area (energy per area) or equivalently the force per unit length at a fluid interface that resists surface area increase and interface deformation; commonly denoted γ (N·m−1) for liquid–gas or liquid–liquid interfaces under quasi‑static conditions.