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

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

1 answer

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.