What must molecules absorb enough thermal energy to overcome to achieve boiling?

Answer

The attractive forces holding them together in the liquid phase (IMFs)

Boiling requires molecules to absorb enough thermal energy (kinetic energy) to overcome the intermolecular forces (IMFs) that keep them clustered in the condensed liquid phase, allowing them to enter the gaseous state.

What must molecules absorb enough thermal energy to overcome to achieve boiling?
attractionmoleculeboiling pointintermolecular forcephase transition