Question

A solid becomes a gas through a process called?

1) condensation
2) freezing
3) sublimation
4) evaporation

Answer 1

Sublimation is the phase transition of a substance from a solid to a gas without passing through the liquid phase, as seen with dry ice and iodine. Its reverse process is deposition, where gas forms a solid directly.

Step-by-step explanation:

Sublimation

is the process through which a solid changes directly into a gas without passing through the liquid phase. For example, when

dry ice

(solid CO₂) is at room temperature and standard pressure, it sublimes, transitioning from a solid to a gas. This process can be observed when solid iodine is warmed and produces a vivid purple vapor. The opposite of sublimation is called

deposition

, which occurs when a gas changes directly into a solid state, bypassing the liquid phase; a common example of this is the formation of frost.