What term describes a colloidal suspension of solid or liquid particles in air?

• A. Aerosol
• B. Fumes
• C. Mist
• D. Smoke

Answer: (B)

An aerosol is a colloidal system in which solid or liquid particles are dispersed in a gas. In air, these particles can be tiny solids or droplets suspended by motion and turbulence, which matches the idea of a colloidal suspension in a gas. This makes aerosol the broad, inclusive term for describing solid- or liquid-particle suspensions in air.

Fumes refer specifically to particles formed from the vapor or sublimed state that then condense, often into solid particles, and are a narrower, more particular type of aerosol. Mist describes liquid droplets dispersed in air, while smoke denotes solid particles from combustion. All of these are aerosols in the broader sense, but they’re more specific cases. The term that best fits “colloidal suspension of solid or liquid particles in air” is aerosol.