Melting (sometimes called fusion)'s a physical process that results in the phase change of a substance from a solid to a liquid. The internal energy of a solid substance's increased, typically by the application of heat or pressure, resulting in a rise of its temperature to the melting point, at which the rigid ordering of molecular entities in the solid breaks down to a less-ordered state and the solid liquefies. An object that's melted completely's molten. Melting point Under a standard set o… (More on Melting)