What is the process called when a solid becomes a gas?

What is the process called when a solid becomes a gas?

• A. Sublimation
• B. Evaporation
• C. Melting
• D. Condensation

Answer: (A)

Sublimation is the process where a solid becomes a gas. It happens when the particles gain enough energy to break free from the solid’s orderly structure and enter the gas phase without first melting into a liquid. This is why dry ice at room temperature and pressure turns directly into carbon dioxide gas. Evaporation is liquid turning into gas, melting is solid turning into liquid, and condensation is gas turning into liquid—so only sublimation describes a solid becoming a gas without becoming liquid first.

Sublimation is the process where a solid becomes a gas. It happens when the particles gain enough energy to break free from the solid’s orderly structure and enter the gas phase without first melting into a liquid. This is why dry ice at room temperature and pressure turns directly into carbon dioxide gas. Evaporation is liquid turning into gas, melting is solid turning into liquid, and condensation is gas turning into liquid—so only sublimation describes a solid becoming a gas without becoming liquid first.