Which phenomenon occurs when solids turn into liquids?

The phenomenon that occurs when solids turn into liquids is known as melting. This process involves the absorption of heat, causing the particles within the solid to gain energy and begin to move more freely, transitioning the material from a rigid structure to a fluid state. Melting is a specific phase change that typically occurs at a defined temperature, known as the melting point, for each material.

In contrast, evaporation refers to the process where liquids turn into gases, often occurring at the surface of the liquid. Condensation is the reverse, where gases turn into liquids. Sublimation is a process where solids convert directly into gases without passing through the liquid phase, as seen with materials like dry ice. Each of these processes involves changes in state but does not describe the transition from solid to liquid, which is specifically defined as melting.