The aerosol is a kind of colloid in which :

Options

A. liquid is dispersed in water
B. gas is dispersed in liquid
C. gas is dispersed in solid
D. solid is dispersed in gas

Explanation

To solve the question regarding aerosols as a type of colloid, we can break down the concepts step by step:

### Step-by-Step Solution:

1. **Understanding Colloids**:
- A colloid is a mixture where one substance (the dispersed phase) is distributed evenly throughout another substance (the dispersion medium).

2. **Identifying the Phases**:
- In a colloidal system, there are two main components:
- **Dispersed Phase**: This acts like the solute in a solution.
- **Dispersion Medium**: This acts like the solvent in a solution.

3. **Defining Aerosols**:
- An aerosol is a specific type of colloid where the dispersion medium is a gas.

4. **Components of Aerosols**:
- In aerosols, the dispersed phase can be either solid particles or liquid droplets.
- Therefore, aerosols consist of tiny solid or liquid particles dispersed in a gas.

5. **Conclusion**:
- Based on the definitions and characteristics, we can conclude that aerosols are colloids where solid or liquid particles are dispersed in a gas.

### Final Answer:
Aerosols are a kind of colloid in which solid or liquid particles are dispersed in a gas.