szublimációdeszublimáció

Sublimation and desublimation are related phase transitions of matter. Sublimation is the direct transition of a substance from the solid to the gas phase, bypassing the liquid phase. This process occurs when the vapor pressure of the solid exceeds the surrounding atmospheric pressure at a given temperature. A common example of sublimation is dry ice (solid carbon dioxide) turning directly into gaseous carbon dioxide at room temperature and standard atmospheric pressure. Other substances that can sublimate include iodine and naphthalene.

Desublimation, also known as deposition, is the reverse process of sublimation. It is the direct transition of a substance from the gas phase to the solid phase, again bypassing the liquid phase. This occurs when the temperature of the gas is lowered below its freezing point, causing the gas molecules to directly form a solid structure. Frost forming on a cold windowpane is a familiar example of desublimation, where water vapor from the air transitions directly into ice crystals. Another example is the formation of snow crystals from atmospheric water vapor. Both processes are endothermic (requiring energy for sublimation) and exothermic (releasing energy for desublimation).