Colloidal particles carry charge is best shown by:

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding Colloidal Particles:**
Colloidal particles are small particles that are dispersed in a medium (liquid or gas). They can carry a charge, which is crucial for their behavior in different environments.

2. **Identifying the Charge:**
The charge on colloidal particles can be determined by observing their movement in an electric field. When an electric field is applied, charged particles will migrate towards the electrode with the opposite charge.

3. **Electrophoresis:**
The process of moving colloidal particles under the influence of an electric field is known as electrophoresis. If the colloidal particles move towards the anode (positive electrode), they are negatively charged. Conversely, if they move towards the cathode (negative electrode), they are positively charged.

4. **Example Observation:**
For instance, if we take a colloidal solution of As2O3 (arsenic trioxide) and apply an electric field, the negatively charged particles will migrate towards the anode. This movement confirms their negative charge.

5. **Conclusion:**
The best way to demonstrate that colloidal particles carry a charge is through the process of electrophoresis. This method allows us to visually confirm the charge of colloidal particles based on their movement in an electric field.

**Final Answer:**
Colloidal particles carry charge is best shown by electrophoresis.

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