What are the phase change processes taking place when a substance is in equilibrium between liquid and gas phases? a. melting and boiling b. expanding and contracting c. evaporating and condensing d. freezing and thawing

 C. Evaporating and condensing

Explanation:  Phase change process id the process in which the phase of one substance is transforming into the another.

These chemical process of transformation can takes place under dynamic equilibrium in which conversion of one phase is in equilibrium with the another one.

In this liquid phase is transforming into the gas phase which is known as Evaporation and gaseous phase is converting back into the liquid phase which is known as Condensation.