A state of dynamic equil has been reached. As long as the P of this vapor is less than the P of the atm pushing down on the surface of the liquid, the bubbles will collapse. The bubbles don't collapse, they get bigger. More and more bubbles form and escape form the water as steam. Process is called boiling.
Vaporization is an endothermic process.
The amt of heat necessary to vaporize a given amt of a liq is called its heat of vaporization. E added to the liquid is used to break the attractive forces. C. Freezing and melting are opposite processes. They involve smaller E chges than vaporization and condensation. FP the T at which the solid and liq forms of a subs exist in equil.