Brownian motion is a/an

Options

A. Electrical property
B. Mechanical property
C. Optical property
D. Colligative property

Answer

**Step-by-Step Solution:**

1. **Understanding Brownian Motion**: Brownian motion refers to the random, zig-zag movement of microscopic particles suspended in a fluid (liquid or gas). This phenomenon is a result of collisions between the suspended particles and the molecules of the fluid.

2. **Historical Context**: The term "Brownian motion" is named after the botanist Robert Brown, who first observed this motion in 1827 while studying pollen grains in water.

3. **Characteristics of Brownian Motion**:
- It occurs in various types of colloidal solutions, including solid in liquid, liquid in liquid, gas in liquid, solid in gas, and liquid in gas.
- The motion is irregular and continuous, and it is influenced by the thermal energy of the fluid molecules.

4. **Classification of Properties**: The question provides four options: electrical property, mechanical property, optical property, and colligative property. To classify Brownian motion:
- **Electrical Property**: Relates to the behavior of charged particles in an electric field.
- **Mechanical Property**: Involves the motion and forces acting on physical bodies.
- **Optical Property**: Concerns how materials interact with light.
- **Colligative Property**: Relates to properties that depend on the number of solute particles in a solution.

5. **Conclusion**: Since Brownian motion describes the mechanical behavior of particles in a fluid due to thermal motion, it is classified as a mechanical property.

**Final Answer**: Brownian motion is a mechanical property.

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