a.Sublimation is the process of transformation DIRECTLY from the solid phase to the gaseous phase, without passing through an intermediate liquid phase. ... In these CASES, the transition from the solid to the gaseous state requires an intermediate liquid state.b.The process of a liquid becoming a gas is called boiling (or vapourization), while the process of a gas becoming a liquid is called condensation.c.The process of a solid becoming a liquid is called melting. (an older TERM that you may see sometimes is fusion). ... For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance. It requires energy for a solid to melt into a liquid.d.Liquid to gas phase transitions are known as "vaporization." Liquid to solid phase transitions are known as "FREEZING." Solid to liquid phase transitions are known as "melting." Solid to gas phase transitions are known as "sublimation." In most cases, SOLIDS turn into gases only after an intermediate liquid state.