Question

Which of the following processes describes the direct transition of a substance from a solid state to a gaseous state without passing through the liquid state?

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

Hint:

Remember the shortcut: \[ \text{Solid} \rightarrow \text{Gas} = \text{Sublimation} \] \[ \text{Gas} \rightarrow \text{Solid} = \text{Deposition} \] Examples of sublimation: Camphor, Iodine, Naphthalene, Dry Ice.

Answer 1

The Correct Option is C

Step 1: Understand the change.
We need the process where a solid turns straight into a gas without becoming a liquid first.

Step 2: Name it.
This direct change, $\text{Solid} \rightarrow \text{Gas}$, is called sublimation.

Step 3: Examples.
Camphor, naphthalene balls and dry ice all sublime. That is why naphthalene balls slowly vanish in open air.

Step 4: Rule out others.
Evaporation is liquid to gas. Condensation is gas to liquid. Deposition is gas to solid.

Step 5: Conclude.
The solid-to-gas change is sublimation.

Answer: Sublimation