These phenomena cause topological defects such as “domain walls” during early universe expansion. Landau’s mean field formulation of these phenomena assumes no long-range correlation and characterizes these phenomena into universality classes. Paul Ehrenfest classified these phenomena based on which order derivative of G (10[1])becomes discontinuous. (10[1])Spontaneous magnetization in (10[1])the two-dimensional Ising model (10[1])occurs during these phenomena at the Curie point. (-5[2])These phenomena occur at coexistence curves on a pressure-temperature diagram (10[1])and may be accompanied by the release or absorption of latent heat. These phenomena (10[1])do not occur past a critical point. (10[1])For 10 points, name these phenomena where one state of matter becomes another. ■END■ (10[2])