Solidliquidgas

Solidliquidgas is not a formal term in physics, but it can be used to refer to the three fundamental states of matter—solid, liquid, and gas—and to the transitions among them. These phases differ in how particles are arranged, their densities, and their compressibility, and they emerge from the balance of intermolecular forces, temperature, and pressure.

Phase transitions connect the states: melting (solid to liquid), freezing (liquid to solid), vaporization (liquid to gas), condensation (gas to liquid), sublimation (solid to gas), and deposition (gas to solid). Transitions occur when energy is added or removed, and many involve latent heat—the energy absorbed or released at a given pressure during the transition.

Phase diagrams plot temperature against pressure to map the boundaries between solid, liquid, and gas phases. The triple point is the unique condition where all three phases coexist in equilibrium; the critical point is where the liquid and gas become indistinguishable. Carbon dioxide provides a common example: at low pressures it sublimates directly from solid to gas, while at higher pressures it can form a liquid. Its triple point lies near -56.6°C and 5.1 atmospheres, and its critical point near 31.0°C and 72.8 atmospheres.

Understanding solidliquidgas has practical implications across material processing, meteorology, cryogenics, and safety in handling volatile substances. The concept underscores that matter can occupy a spectrum of states and that phase behavior depends on environmental conditions as well as composition.