When vapour pressure of a liquid is equal to the atmospheric pressure, what happens to the liquid?

The temperature at which the vapour pressure of a liquid equals the atmospheric pressure is called its:

Which one of the following regarding density of water at atmospheric pressure is correct ?

Evaporation from the surface of a given liquid takes place more rapidly when

The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. Why?

In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following?