Which of the following is/are aerosols?

Options

A. Smoke
B. Milk
C. Butter
D. Fog

Explanation

To determine which of the given options are aerosols, we need to understand the definition of aerosols and analyze each option accordingly.

### Step-by-Step Solution:

1. **Understanding Aerosols**:
- Aerosols are colloidal systems where the dispersion medium is a gas, and the dispersed phase can be either solid or liquid.

2. **Analyzing the Options**:
- **Option 1: Smoke**
- **Dispersion Medium**: Gas (air)
- **Dispersed Phase**: Solid particles (carbon, ash, etc.)
- **Conclusion**: Smoke fits the definition of an aerosol. **(Correct)**

- **Option 2: Milk**
- **Dispersion Medium**: Liquid (water)
- **Dispersed Phase**: Liquid (fat globules)
- **Conclusion**: Milk is an emulsion, not an aerosol. **(Incorrect)**

- **Option 3: Butter**
- **Dispersion Medium**: Liquid (water)
- **Dispersed Phase**: Liquid (fat)
- **Conclusion**: Butter is also an emulsion, not an aerosol. **(Incorrect)**

- **Option 4: Fog**
- **Dispersion Medium**: Gas (air)
- **Dispersed Phase**: Liquid (tiny water droplets)
- **Conclusion**: Fog fits the definition of an aerosol. **(Correct)**

3. **Final Conclusion**:
- The options that are aerosols are **Smoke** and **Fog**.

### Summary of Correct Options:
- **Correct Answers**: Smoke and Fog