Question

What is involved in the process that is opposite to sublimation? Do you think such a process exists? Why? why not?

Answer 1

Hint: Sublimation is the process of a material transitioning directly from a solid to a gas state without going through a liquid stage. Sublimation is an endothermic process that happens when a material's triple point on its phase diagram, which corresponds to the lowest pressure at which the substance can exist as a liquid, is reached.

Complete answer:
Deposition or desublimation is the reversal of sublimation, in which a material transitions from a gas to a solid state.
Deposition happens when molecules settle out of a solution in chemistry. Deposition is similar to dissolution or particle re-entrainment in that it occurs in the other direction. Re-sublimation is a phase transition from a gaseous to a solid state without going through the liquid stage. Deposition is a phase transition in which a gas becomes a solid without first passing through the liquid phase. Thermodynamics govern the process of deposition. Sublimation is the inverse of deposition, therefore deposition is also referred to as desublimation.
The process by which water vapour turns straight to ice in sub-freezing air without first becoming a liquid is an example of deposition. Frost and hoar frost grow on the ground and other surfaces in this manner. When frost develops on a leaf, for example. Thermal energy must be taken from a gas in order for deposition to occur. Water vapour in the air surrounding the leaf loses enough thermal energy to solidify when it turns cold enough. Even though the air temperature is below the dew point, if there is no mechanism to eliminate the latent heat, the water vapour may not be able to condense spontaneously.
The supercooled water vapour begins to condense as soon as the leaf is inserted, but it has already beyond the freezing point. As a result, the water vapour transforms into a solid.
Another example is the soot that accumulates on chimney walls. Soot molecules are heated and gaseous when they ascend from the fire. They cool and convert to a solid state when they come into contact with the walls, rather than forming a liquid state. The method is used in combustion chemical vapour deposition in industry.

Note:
Evaporative deposition is an industrial coating process in which a solid material is heated to a gaseous state in a low-pressure chamber, the gas molecules move across the chamber space, and then deposit to the solid state on a target surface, creating a smooth and thin layer. When moving from a gas to a solid, the molecules do not pass through an intermediate liquid stage. See also physical vapour deposition, a group of techniques for depositing thin films of different materials onto a variety of surfaces.
Deposition is an exothermic phase transition that releases energy.