Question

Which of the following are examples of aerosols
A) whipped cream
B) Cloud
C) Fog
D) soap lather

Answer 1

An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic.

Complete step by step solution:
A) whipped cream is an example of gas in liquid type colloid. Solution is a colloidal suspension with solid particles in a liquid:
B) When the dispersion medium is gas, the dispersed phase can be solid or liquid but not the gas. Colloids of gas with dispersed phase as solids or liquids are called Aerosols. Fog is an example of an aerosol particle thus cloud or fog is a colloidal system in which the dispersed phase is liquid and the dispersion medium is gas.
C) Examples of natural aerosols are fog, mist, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are particulate air pollutants and smoke. The liquid or solid particles have diameters typically less than $1\;\mu m$ ; larger particles with a significant settling speed make the mixture a suspension, but the distinction is not clear-cut.
D) Soap lather is an example of foam. Dispersion medium is liquid and the dispersed phase is gas.

**Options “B” and “C” are correct.

Additional Information**
Aerosols are minute particles suspended in the atmosphere. When these particles are sufficiently large, we notice their presence as they scatter and absorb sunlight. Their scattering of sunlight can reduce visibility (haze) and redden sunrises and sunsets.
Aerosols interact both directly and indirectly with the Earth's radiation budget and climate. As a direct effect, the aerosols scatter sunlight directly back into space. As an indirect effect, aerosols in the lower atmosphere can modify the size of cloud particles, changing how the clouds reflect and absorb sunlight,

Note:
Aerosols also can act as sites for chemical reactions to take place. The most significant of these reactions are those that lead to the destruction of stratospheric ozone. During winter in the polar regions, aerosols grow to form polar stratospheric clouds. The large surface areas of these cloud particles provide sites for chemical reactions to take place. These reactions lead to the formation of large amounts of reactive chlorine and, ultimately, to the destruction of ozone in the stratosphere.