Question

Question Aerosols include all the following EXCEPT: a. smoke b. mists c. dusts d. vapor

Answer 1

AEROSOLS:

An aerosol is a colloidal suspension of fine solid particles or liquid droplets dispersed in air or gas. Aerosols can be natural or anthropogenic(originating in human activity). Examples of natural aerosols are fog and dust. Examples of anthropogenic aerosols are haze and particulate air pollutants.

Question :

Aerosols include all the following EXCEPT: a. Smoke b. Mists c. Dusts d. Vapour

Answer:

Of the above, smoke, mist and dust are aerosols but not vapour.

Smoke: It is a visible suspension of carbon or other particles in air, typically one emitted from a burning substance. It is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. Thus smoke is an aerosol.

Mist: It is a cloud of tiny water droplets suspended in the atmosphere at or near the earth's surface that limits visibility.It is a phenomenon caused by small droplets of water suspended in air. Thus mist is also an aerosol.

Dust: Dust are fine particles of matter. It generally consists of particles in the atmosphere. Dust in the atmosphere is produced by saltation and sandblasting of sand-sized grains, and it is transported through the troposphere. This airborne dust is considered an aerosol and once in the atmosphere, it can produce strong local radiative forcing.

Vapour: It is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapour can be condensed to a liquid by increasing the pressure on it without reducing the temperature. Vapour is gaseous state of a liquid (generally water) and not a colloid. Thus vapour is not an aerosol.