állapotváltozás

Állapotváltozás, often translated as phase transition or state change, refers to the physical process where a substance transforms from one state of matter to another. These transformations are driven by changes in temperature and pressure. The most common examples involve transitions between solid, liquid, and gaseous states.

A solid to liquid transition is called melting or fusion, occurring when a substance absorbs enough energy to overcome the intermolecular forces holding its particles in a fixed structure. The reverse process, liquid to solid, is known as freezing or solidification.

Liquid to gas transformations are called vaporization or boiling. This happens when particles gain sufficient kinetic energy to escape the liquid surface and become free-moving gas molecules. The reverse process, gas to liquid, is condensation.

Sublimation is a direct transition from solid to gas, bypassing the liquid phase. Dry ice (solid carbon dioxide) is a common example. The opposite process, gas to solid, is deposition. Transitions between different solid forms, such as allotropic changes in elements like carbon (graphite to diamond), also fall under the umbrella of state changes.

These transitions occur at specific temperatures and pressures for each substance, known as transition points. For example, water melts at 0 degrees Celsius and boils at 100 degrees Celsius at standard atmospheric pressure. Understanding state changes is fundamental in chemistry and physics, with applications ranging from weather patterns to industrial processes.