The temperature at which a liquid and gaseous phases are in equilibrium is called the boiling point of the liquid.

Here's why:

* Equilibrium: This means that the rate of molecules transitioning from liquid to gas (evaporation) is equal to the rate of molecules transitioning from gas to liquid (condensation).

* Boiling point: The boiling point is the specific temperature where this equilibrium occurs under a given pressure, typically atmospheric pressure.

At the boiling point, the liquid and gaseous phases coexist and the vapor pressure of the liquid equals the surrounding pressure.