In a liquid, the energy required to increase the surface of the area by a unit amount is called : a. dipole-dipole force. b. viscosity. c. capillary action. d. surface tension. e. hydrogen bonding

D. Surface tension.

Explanation:

Surface tension is defined as the energy required to increase the surface area of a liquid by a unit amount.

The surface tension of a liquid results from an imbalance of intermolecular attractive forces, the cohesive forces between molecules:

A molecule in a liquid experiences cohesive forces with other molecules in all directions while molecules at the surface of a liquid experiences only net inward cohesive forces.