Colloidal particles carry charge is best shown by:

Options

A. Brownian movement
B. Tyndall effect
C. Electrophoresis
D. Dialysis

Answer

To solve the question "Colloidal particles carry charge is best shown by:", we will analyze the options provided and determine which one correctly demonstrates that colloidal particles carry a charge.

### Step-by-Step Solution:

1. **Understanding Brownian Movement**:
- Brownian movement refers to the random zigzag motion of colloidal particles suspended in a fluid. This movement is caused by the collisions of the particles with the molecules of the dispersion medium.
- **Conclusion**: Brownian movement does not indicate that colloidal particles carry a charge. Therefore, this option is incorrect.

2. **Understanding Tyndall Effect**:
- The Tyndall effect is the scattering of light by colloidal particles, which makes the path of the light beam visible in a colloidal solution.
- **Conclusion**: The Tyndall effect demonstrates the presence of colloidal particles but does not provide evidence of charge. Thus, this option is also incorrect.

3. **Understanding Electrophoresis**:
- Electrophoresis is the movement of colloidal particles under the influence of an electric field. When an electric field is applied, colloidal particles migrate towards the oppositely charged electrode.
- This movement indicates that colloidal particles carry a charge, as they respond to the electric field.
- **Conclusion**: Electrophoresis clearly shows that colloidal particles carry a charge. Therefore, this option is correct.

4. **Understanding Dialysis**:
- Dialysis is the process of separating colloidal particles from smaller particles (like ions) using a semi-permeable membrane. Colloidal particles cannot pass through the membrane, while smaller ions can.
- **Conclusion**: Dialysis does not demonstrate that colloidal particles carry a charge. Hence, this option is incorrect.

### Final Answer:
The correct answer is **Electrophoresis**, as it best demonstrates that colloidal particles carry a charge.

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