What process occurs when a solid changes into a liquid?

The process that occurs when a solid changes into a liquid is known as melting. This transformation takes place when the solid absorbs enough heat energy, causing its particles to gain kinetic energy. As a result, these particles begin to move more freely and break the rigid structure of the solid, transitioning into the liquid state.

In contrast, condensation refers to the process where a gas changes into a liquid, typically due to a drop in temperature. Evaporation is the process where a liquid turns into a gas, which occurs at the surface of the liquid when sufficient energy is available. Sublimation describes the transition of a solid directly to a gas without passing through the liquid phase, as seen with substances like dry ice. These processes are distinct and represent different physical changes, with melting specifically defined as the solid-to-liquid transition.