2. Adhesive strength (recommended symbol: $$F_{\text{a}}$$, unit: $$\text{N m}^{-2}$$) is the force required to separate one condensed @[email protected] from another at the @[email protected] between the two phase domains divided by the area of the @[email protected]
3. @[email protected] (recommended symbol: $$\gamma$$, unit: $$\text{N m}^{-1}$$, $$\text{J m}^{-2}$$) is the change in Gibbs energy per unit change in interfacial area for substances in physical contact.