Stoffübergängen

Stoffübergängen, a German term often translated as "phase transitions" or "material transfer," refers to the process where a substance changes from one state of matter to another. These transitions are driven by changes in temperature and pressure. Common examples include melting, where a solid becomes a liquid, and boiling, where a liquid becomes a gas. The reverse processes are freezing (liquid to solid) and condensation (gas to liquid). Sublimation is a less common transition where a solid directly becomes a gas, bypassing the liquid phase, while deposition is the reverse process.

During a stoffübergang, the internal energy of the substance changes. For example, energy is absorbed during melting and boiling to overcome intermolecular forces. Conversely, energy is released during freezing and condensation as these forces become re-established. The specific temperature and pressure at which a stoffübergang occurs are known as the transition point, such as the melting point or boiling point. These points are characteristic properties of a pure substance and can be used for identification. Understanding stoffübergängen is fundamental in various scientific disciplines, including chemistry, physics, and materials science, and has practical applications in industries ranging from food processing to manufacturing.