Bonding and Phase Changes? When water boils into water vapor, its temperature (average kinetic energy) does not change because the inputed energy is used to break its bonds. But how does that work?

Also, in a liquid, aren’t intermolecular bonds broken and reformed constantly anyway? Why does a phase change require a time interval for breaking bonds?
Temperature involves kinetic energy; however, bonds and intermolecular forces (IMF's) involve potential energy.  The potential energy of the system increases when water vaporizes, but kinetic energy does not change.

In a liquid, for each IMF broken, another is made, resulting in a net change of zero.

A phase change requires a time interval because it takes time to add energy to the system.