What change of state involves a gas becoming a solid directly?

What change of state involves a gas becoming a solid directly?

• A. Freezing
• B. Sublimation
• C. Deposition
• D. Vaporization

Answer: (C)

The process where a gas transforms directly into a solid is known as deposition. During this phase change, molecules in the gas state lose energy and transition to a solid state without going through the liquid phase. This phenomenon is best illustrated by examples such as frost formation on cold surfaces, where water vapor in the air solidifies directly into ice crystals. This process is the opposite of sublimation, where a solid converts directly into a gas. Understanding deposition is crucial in hazardous materials incidents, as certain gases can solidify upon cooling, impacting containment and cleanup strategies.

The process where a gas transforms directly into a solid is known as deposition. During this phase change, molecules in the gas state lose energy and transition to a solid state without going through the liquid phase. This phenomenon is best illustrated by examples such as frost formation on cold surfaces, where water vapor in the air solidifies directly into ice crystals. This process is the opposite of sublimation, where a solid converts directly into a gas. Understanding deposition is crucial in hazardous materials incidents, as certain gases can solidify upon cooling, impacting containment and cleanup strategies.