When water vapour directly forms ice crystals on ice particles which process is involved?

Correct answer: जमाव

Correct answer: A. Deposition is the direct change of a substance from the gaseous state to the solid state without first becoming liquid. In this case, water vapour changes directly into solid ice on or around an ice particle, so ice crystals grow. This process can occur in cold clouds and is important in the formation and growth of ice crystals that may later contribute to snow or other frozen precipitation. Option A is correct because it names the gas-to-solid change. Option B, evaporation, is the opposite type of change: liquid water becomes water vapour. Option C, melting, is a solid-to-liquid change, such as ice becoming liquid water when heated. Option D, boiling, is a rapid liquid-to-gas change occurring throughout a liquid at its boiling point; it does not describe ice-crystal growth from vapour. The word “directly” is the key clue: vapour goes straight to solid ice and skips the liquid stage. In some school texts, this gas-to-solid change may also be called reverse sublimation, while sublimation usually refers to solid changing directly into gas. Memory cue: deposition deposits vapour as solid ice.