Which process involves the change of matter from a solid directly to a gas?

Sublimation is the process wherein a solid transitions directly into a gas without first becoming a liquid. This direct change occurs under specific conditions of temperature and pressure. Common examples include dry ice (solid carbon dioxide) and iodine, which can sublimate at standard atmospheric pressure when exposed to the right conditions.

Evaporation refers to the process where a liquid transforms into a gas, typically occurring at the surface of the liquid, while melting involves a solid changing into a liquid. Condensation, on the other hand, is the reversal of evaporation where a gas becomes a liquid. Understanding these processes is critical in various scientific and practical applications, including those in the field of aesthetics and skincare, where knowledge about physical properties and processes is essential.