állapotváltozásos

Az állapotváltozásos, or phase transition, refers to a physical process where a substance changes from one state of matter to another. These changes occur at specific temperatures and pressures. The most common examples involve transitions between solid, liquid, and gaseous states.

Melting, or fusion, is the transition from a solid to a liquid. This happens when a solid absorbs enough thermal energy to overcome the forces holding its particles in a fixed structure. The temperature at which this occurs is called the melting point. Conversely, freezing, or solidification, is the transition from a liquid to a solid, occurring when a liquid loses thermal energy.

Boiling, or vaporization, is the transition from a liquid to a gas. This occurs when a liquid absorbs enough heat to break free from intermolecular forces and enter the gaseous phase. The temperature at which this happens is the boiling point. Condensation is the reverse process, where a gas turns into a liquid upon cooling.

Sublimation is a less common phase transition where a substance changes directly from a solid to a gas without passing through the liquid state. Dry ice, which is solid carbon dioxide, is a common example. Deposition is the opposite of sublimation, where a gas directly transforms into a solid.

These phase transitions are governed by thermodynamic principles and involve changes in internal energy, entropy, and enthalpy. The specific conditions required for each state change depend on the substance's chemical composition and intermolecular forces.