Interconversion of solids, liquids and gases
Questions on the particle theory of matter show interconversion of states with a reversible arrow: ⇌, which means that the process can go forwards and backwards. Read the question carefully and pick the direction of the change in state that the question refers to.
Sublimation is no longer part of the syllabus, but you can see how it fits in on the interconversion diagram with the other state changes.
A heating curve showing the states, state changes and temperature changes as time progresses
A cooling curve is like a heating curve, but is the mirror image