What is Desublimation?
[[File:Frost_patterns_4.jpg|thumb|300px|[[Water vapor]] from humid winter-air deposits directly into a solid, crystalline frost pattern on a window, without ever being liquid in the process.]] '''Desublimation''' is a [[phase transition]] in which [[gas]] turns into [[solid]] without passing through the [[liquid]] state. It is the reverse of [[Sublimation (phase transition)|sublimation]]. It is how [[snow]] forms in [[cloud]]s, and how [[frost]] and [[hoar frost]] form on the ground or on windows. Another example is the [[soot]] on walls of [[chimney]]s. Soot molecules rise from the fire in a hot and gaseous state. When they come into contact with the walls they cool, and change to the solid state, without forming the liquid state. The process is sometimes known as '''deposition (phase transition)'''. {{physics-stub}} [[Category:States of matter]]