What is the process by which a gas is converted into a solid?

Correct option is A

The correct answer is (a) Deposition
Explanation:
. Deposition is the process in which a gas directly changes into a solid without passing through the liquid state.
. It is the reverse process of sublimation.
. During deposition, energy is released, making it an exothermic process.
. Common natural examples include frost formation and snowflake formation from water vapour.
. This process occurs under conditions of low temperature and sufficient pressure.
Information Booster:
. Deposition is observed when water vapour directly forms ice crystals on cold surfaces.
. Iodine vapour forming solid iodine crystals is another example of deposition.
Additional Knowledge:
Sublimation (Option b)
. Sublimation is the direct change of a solid into a gas.
. Examples include camphor, naphthalene, and dry ice.
Vaporisation (Option c)
. Vaporisation is the change of a liquid into a gas.
. It occurs through evaporation or boiling.
Freezing (Option d)
. Freezing is the conversion of a liquid into a solid.
. It does not involve the gaseous state.