Which of the following groups of colloids contains
members of only aerosol?

Options

A. Milk, cloud, froth
B. Paints, dust, fog
C. Cheese, milk, mist
D. Smoke, fog, cloud

Answer

To determine which group of colloids contains only aerosols, we first need to understand what aerosols are. Aerosols are colloidal systems where solid or liquid particles are dispersed in a gas.

Now, let's analyze each of the given options:

1. **Milk - Cloud - Frost**:
- Milk is a colloidal suspension of fat globules in water, not an aerosol.
- Cloud is an aerosol since it consists of tiny water droplets dispersed in air.
- Frost is not an aerosol; it is a solid deposit of water vapor.

**Conclusion**: This group contains non-aerosol members.

2. **Paint - Dust - Fog**:
- Paint is a colloidal mixture, but it is not an aerosol as it is primarily a liquid with pigments.
- Dust consists of solid particles, and when suspended in air, it can be considered an aerosol.
- Fog is an aerosol as it consists of tiny water droplets dispersed in air.

**Conclusion**: This group contains non-aerosol members (paint).

3. **Cheese - Milk - Mist**:
- Cheese is a solid colloid and not an aerosol.
- Milk is a colloidal suspension, not an aerosol.
- Mist is an aerosol as it consists of tiny water droplets dispersed in air.

**Conclusion**: This group contains non-aerosol members (cheese and milk).

4. **Smog - Fog - Cloud**:
- Smog is an aerosol that consists of a mixture of smoke and fog, with solid and liquid particles dispersed in air.
- Fog is an aerosol as it consists of tiny water droplets in air.
- Cloud is also an aerosol, consisting of water droplets or ice crystals in the air.

**Conclusion**: This group contains only aerosols.

After analyzing all the options, we can conclude that the fourth option (Smog - Fog - Cloud) contains only aerosols.

**Final Answer**: The group that contains members of only aerosols is **Smog - Fog - Cloud**.

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