Which term describes the airborne particles suspended in air, as used in this context?

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

Answer: (D)

Airborne particles suspended in air come from substances that vaporize and then condense into very fine particles that float in the gas. Fumes describe this precisely: solids or liquids that have been heated or vaporized and then reform as tiny particles that remain suspended in air. This is distinct from mist, which is fine liquid droplets formed by atomization; dust, which is solid particles produced by mechanical actions; and aerosols, a broad term for any suspension of particles in a gas. In lab safety language, the lingering particles produced by heating or chemical reactions are often called fumes, so this term fits the described context.