The process of converting a gas directly to a solid is called:

**The reasoning** When a gas transforms **directly** into a solid *without* passing through the liquid phase, we call this **deposition**. Think of it like this: the gas molecules slow down so much (usually due to cooling) that they arrange themselves into a solid structure immediately. A real-world example? Frost forming on your car windscreen on a cold harmattan morning! Water vapor in the air goes straight to ice crystals (solid) without becoming liquid water first. The key principle: **Phase transitions have specific names based on direction**: - Solid → Gas = Sublimation - **Gas → Solid = Deposition** ✓ **Why the wrong options tempt you** - **Sublimation (C)** is the reverse process (solid → gas), like camphor balls disappearing. Many students mix these two up because sublimation is more commonly discussed. - **Evaporation (A)** is liquid → gas (water drying from clothes). - **Condensation (B)** is gas → liquid (dew drops on grass in the morning). **Quick takeaway** Remember: "**Deposition deposits a solid from a gas**" — the word itself hints that something is being *deposited* or laid down in solid form.