Aggregatzustand

Aggregatzustand, or state of matter, refers to the distinct forms in which matter can exist, defined by the arrangement and energy of its particles and by the relative strength of their interactions. The most common states are solid, liquid, and gas. Other states include plasma, where electrons are stripped from atoms, and various quantum states such as Bose-Einstein condensates that occur at very low temperatures. In some conditions, fluids can become supercritical, lacking a clear boundary between liquid and gas.

Transitions between states are driven primarily by changes in temperature and pressure and are described by phase diagrams. When heat is added or removed, materials can melt or freeze, vaporize or condense, or undergo sublimation (solid to gas) and deposition (gas to solid). Each transition involves latent heat and characteristic temperatures, such as melting and boiling points, which depend on composition and environment.

Understanding Aggregatzustand is essential in chemistry, physics, materials science, meteorology, and engineering, influencing properties such as density, viscosity, diffusion, and thermal conductivity. Everyday examples include ice melting in water, water boiling to produce steam, and the behavior of air under different atmospheric conditions.

Related topics include phase diagrams, plasma, and supercritical fluids.