Question

The process by which a gas changes to a solid is

Answer 1

The correct answer to the question is - Deposition i.e the process by which a gas changes to a solid is called deposition.

EXPLANATION:

There are various thermal processes of state or phase change in which matter in one state is converted into matter in another state.

Deposition is the type of thermodynamic process of state or phase change in which a gaseous substance is directly converted into corresponding solid substance without entering into liquid phase.

During this process, the loss of thermal energy from gas is very fast. Hence, the gas directly enters solid phase without undergoing into liquid phase.

This process is just the opposite process of sublimation where a solid is converted into gas directly. That's why this process is also known as desublimation.

For instance, conversion of water vapor into ice.

Answer 2

That process is called deposition.