Liquid-Gas Transition

The liquid-gas transition refers to the process where a substance changes between a liquid and a gas. When you heat a liquid enough, its particles gain energy and eventually escape into the air as gas; this is evaporation or boiling. Conversely, cooling a gas causes particles to lose energy and come together into a liquid. The transition occurs at specific pressure and temperature points known as phase boundaries. At certain conditions, the difference between liquid and gas becomes indistinct, reaching a critical point where the substance exists as a supercritical fluid, blending properties of both phases.