In the material, sublimation refers to which phase change?

In the material, sublimation refers to which phase change?

• A. Gas to liquid
• B. Liquid to gas
• C. Solid to liquid
• D. Solid to gas

Answer: (D)

Sublimation is the solid-to-gas phase change: a solid turns directly into a gas without becoming a liquid first. This happens when the particles gain enough energy and the conditions (often low pressure) allow those particles to escape into the gas phase without melting. A common example is dry ice, which at room temperature under normal pressure sublimates from solid CO2 into CO2 gas. This is distinct from melting (solid to liquid) and vaporization (liquid to gas); sublimation bypasses the liquid stage entirely.

Sublimation is the solid-to-gas phase change: a solid turns directly into a gas without becoming a liquid first. This happens when the particles gain enough energy and the conditions (often low pressure) allow those particles to escape into the gas phase without melting. A common example is dry ice, which at room temperature under normal pressure sublimates from solid CO2 into CO2 gas. This is distinct from melting (solid to liquid) and vaporization (liquid to gas); sublimation bypasses the liquid stage entirely.