The movement of colloidal particles towards oppositely charged electrodes on passing electricity is known as :

Options

A. Brownian movement
B. Cataphoresis
C. Tyndall effect
D. None of the above

Explanation

To solve the question, we need to identify the term that describes the movement of colloidal particles towards oppositely charged electrodes when electricity is passed through a colloidal solution.

### Step-by-Step Solution:

1. **Understanding the Context**: The question is about the behavior of colloidal particles in an electric field. When electricity is applied to a colloidal solution, the particles within it respond to the electric field.

2. **Identifying the Movement**: Colloidal particles carry a charge, and when an electric field is applied, these charged particles will move towards the electrode that has the opposite charge. This movement is a key characteristic of colloidal systems.

3. **Defining the Term**: The specific term for the movement of colloidal particles towards oppositely charged electrodes is known as "cataphoresis." This term is derived from the Greek word "cata," meaning "down," and "phoresis," meaning "to carry."

4. **Eliminating Other Options**:
- **Brownian Movement** refers to the random motion of particles in a fluid, which is not related to the application of an electric field.
- **Tyndall Effect** describes the scattering of light by colloidal particles, which is also unrelated to the movement of particles in an electric field.
- The fourth option is not relevant to the question.

5. **Conclusion**: Therefore, the correct answer to the question is "cataphoresis."

### Final Answer:
The movement of colloidal particles towards oppositely charged electrodes on passing electricity is known as **cataphoresis**.

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