Boiling point is defined as the temperature when the vapor pressure is equal to the atmospheric pressure vapor pressure is dependent on temperature and at a specific temperature dynamic equilibrium will be reach between the number of molecules who have enough kinetic energy to escape as a gas from the liquid and the gas molecules who lose energy and condense back into the Liquid. If you want to read more do read up on Vapor pressure and Raoult's law (more in the fields of chemistry and intermolecular forces than physics and thermodynamics)
Also please be more specific with the question, this is all I can help based on what you told me