What is the process of a solid turning directly into a gas called?

The process of a solid turning directly into a gas is called sublimation. This phenomenon occurs without the substance first becoming a liquid, which is what distinguishes it from processes like melting or evaporation. In sublimation, the molecules in the solid gain enough energy to break free from the solid state and transition directly into the gaseous state. A common example of sublimation is dry ice (solid carbon dioxide), which transitions directly to carbon dioxide gas at temperatures and pressures typical at room temperature. This process is important in various applications, including freeze-drying and certain industrial processes.