What is the process called when a solid turns directly into a vapor?

The process in which a solid turns directly into a vapor is known as sublimation. During sublimation, solid particles gain enough energy to overcome their intermolecular forces and escape into the gas phase without first becoming a liquid. This transition typically occurs under specific conditions of temperature and pressure. A common example of sublimation is dry ice (solid carbon dioxide) which, when exposed to room temperature, changes directly into carbon dioxide gas without melting into a liquid.

Understanding sublimation is crucial in various scientific applications, such as in freeze-drying processes, where moisture is removed from food products by sublimating ice. In summary, sublimation describes a direct transition from solid to gas, distinguishing it from other phase changes that involve liquid states.