During which changes of state do atoms that cannot move past one another become free to move?

Question

vaporization and sublimation
boiling and deposition
sublimation and melting
condensation and melting

Answer 1

The correct answer is sublimation and melting.

During sublimation, a solid transitions directly to a gas, allowing the atoms to move freely. During melting, a solid transitions to a liquid, which also permits the atoms to move past one another. In both cases, the constraints that prevent atoms from moving freely are lifted.