For a liquid, the surface tension (force per unit length) and the surface energy density are identical. Water has a surface energy density of 0.072 J/m^2 and a surface tension of 0.072 N/m; the units are equivalent. read more
Surface tension is not equal to surface energy, though they are closely related. Any material - solid or liquid - wants to bond to itself, not something else; that’s why it sticks together into a solid or liquid in the first place. A surface or interface disrupts this bonding, and so incurs an energy penalty. read more
Why you see the difference between the surface tension and the surface energy is that the tension actually is more of an independent factor that independently functions in entropical values whilst the surface energy is more controlled due to the fact that it depends on the units of which the material consists. read more
The surface energy per unit area is identical to the surface tension measured. The units of surface energy are Jm-2. When the surface energy is provided by an external source, the liquid is said to be bubbling. Surface Tension vs Surface Energy. Surface tension has the units of Nm-1 and Jm-2 whereas surface energy has the unit Jm-2. read more