What phase change is shown in the accompanying molecular art? Is the process endothermic or exothermic?
Analysis
Identify the phase by the distance between the spheres and their level of organization. A solid has closely packed spheres that are well organized; a liquid has closely packed but randomly arranged spheres;a gas has randomly arranged spheres that are far apart. Then, classify the transformation as melting,freezing, evaporation, condensation, sublimation, or deposition, depending on the phases depicted.