These occurrences are exemplified by deposition and sublimation.
For many materials, these phenomena are accompanied by a divergence in the length scale on which molecular motion is correlated. Paul Ehrenfest classified these phenomena using order parameters, and the Curie point is a (*) second-order example of them. The coexistence curve represents the parameters along which these occur, and they can no longer occur at the critical point. These occurrences are represented by the crossing of pressure-temperature boundary lines on their namesake diagrams. These occurrences are exemplified by deposition and sublimation. For 10 points, name these occurrences in which one state of matter becomes another.
For many materials, these phenomena are accompanied by a divergence in the length scale on which molecular motion is correlated.
phase transitions (accept phase change or phase transformations or any logical synonym of “transition”; prompt on partial answer, especially just phases)