Question

What is the process of a solid turning directly into a gas called?

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

Hint:

{Sublimation = Solid → Gas directly} (no liquid stage).

Answer 1

The Correct Option is B

Concept: Sublimation is the process in which a substance changes directly from a solid state to a gaseous state without passing through the liquid phase. This occurs when molecules of a solid gain enough energy to escape directly into the gas phase. Common examples include:

• Dry ice (solid \(CO_2\))
• Camphor
• Naphthalene
• Iodine crystals

Step 1: Identify the phase change.
Solid → Gas without becoming liquid is called sublimation.
Step 2: Eliminate other options.

• Condensation is gas → liquid.
• Evaporation is liquid → gas.
• Deposition is gas → solid.

Thus, the direct change of a solid into gas is called sublimation.