Aerosol is suspension of

Options

A. Liquid or solid particles of more than 1 mm
B. Liquid drops in air
C. Liquid or solid particles of less than 1 mm
D. Solid particles in air

Answer

**Step-by-Step Solution:**

1. **Understanding Aerosols**: Begin by defining what aerosols are. Aerosols are mixtures of solid or liquid particles suspended in a gas, typically air.

2. **Analyzing the Options**: Look at the options provided in the question:
- Option 1: Liquid or solid particles of more than one millimeter
- Option 2: Liquid drops in air
- Option 3: Liquid or solid particles of less than one millimeter
- Option 4: Solid particles in air

3. **Identifying the Correct Size**: Aerosols consist of very small particles. The size of these particles is typically less than 1 micrometer (or 0.001 millimeters). This is crucial for the definition of aerosols.

4. **Selecting the Right Definition**: Based on the definition and size of the particles, the correct option would be the one that states "liquid or solid particles of less than one millimeter" (which is equivalent to less than 1 micrometer).

5. **Examples of Aerosols**: Common examples of aerosols include fog, dust, and smoke. These examples illustrate the presence of tiny particles suspended in the air.

6. **Final Answer**: The correct answer to the question is option 3: "liquid or solid particles of less than one millimeter."

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