What is the term for the process where water vapor transforms directly into ice?

The process where water vapor transforms directly into ice is known as deposition. This term specifically describes the phase change in which water vapor, bypassing the liquid state, transitions directly into solid ice. An example of this can be observed in the formation of frost on cold surfaces, where moisture in the air freezes upon contact, illustrating the deposition process.

In contrast, evaporation refers to the transition of water from a liquid state to a gaseous state. Condensation is the reverse, where water vapor changes back to liquid form, such as when dew forms. Sublimation describes the process in which a solid transitions directly to a gas, as seen when dry ice (solid carbon dioxide) sublimates. Each of these terms pertains to different phase changes, with deposition specifically denoting the conversion of vapor to ice.