The temperature at which both liquid and gas phases are identical, is called the __________ point.

ANS:A - critical

The temperature at which both the liquid and gas phases of a substance coexist in equilibrium is called the critical point. At the critical point, the distinction between the liquid and gas phases disappears, and the substance displays properties intermediate between those of a liquid and a gas. Above the critical temperature and pressure, the substance cannot exist in a distinct liquid or gas phase. So, the correct term to fill in the blank is: critical point.