Which option correctly defines an aerosol?

Which option correctly defines an aerosol?

• A. A colloid of gas in a liquid.
• B. Gas dissolved in a solid.
• C. Solid particles in a liquid.
• D. A colloidal suspension of liquid or fine solid particles in a gas.

Answer: (D)

An aerosol is a system where tiny solid particles or liquid droplets are dispersed in a surrounding gas. The key point is that the dispersed phase is solid or liquid, while the continuous medium is gas (like air). That matches the description of a colloidal suspension of liquid or fine solid particles in a gas. Examples include smoke (solid particles in air) and fog or mist (tiny liquid droplets in air). Other scenarios describe gas in a liquid, gas in a solid, or solid in a liquid, which are not aerosols.

An aerosol is a system where tiny solid particles or liquid droplets are dispersed in a surrounding gas. The key point is that the dispersed phase is solid or liquid, while the continuous medium is gas (like air). That matches the description of a colloidal suspension of liquid or fine solid particles in a gas. Examples include smoke (solid particles in air) and fog or mist (tiny liquid droplets in air). Other scenarios describe gas in a liquid, gas in a solid, or solid in a liquid, which are not aerosols.