collodial systems are not classified on the basis of :

Options

A. molecular size
B. nature of the particles
C. suface tension value
D. interaction between disperse phase and dispersion medium

Answer

To answer the question regarding the classification of colloidal systems, we will analyze the criteria based on which colloidal systems are typically classified and identify which one is not used for classification.

### Step-by-Step Solution:

1. **Understanding Colloidal Systems**:
Colloidal systems consist of a dispersed phase and a dispersion medium. The size of the particles in the dispersed phase typically ranges from 1 nanometer to 1000 nanometers.

2. **Classification Based on Molecular Size**:
- Colloidal systems are classified based on the size of the dispersed particles.
- If the particle size is less than 1 nanometer, it is considered a true solution.
- If the particle size is greater than 1000 nanometers, it is classified as a suspension.
- Therefore, molecular size is a valid criterion for classification.

3. **Classification Based on Nature of Particles**:
- Colloids can also be classified based on the nature of the dispersed phase and the dispersion medium.
- Examples include multi-molecular colloids, macromolecular colloids, and associated colloids.
- Thus, the nature of particles is another valid criterion for classification.

4. **Classification Based on Surface Tension Value**:
- Surface tension value is not a criterion used to classify colloidal systems.
- While surface tension can affect the stability and behavior of colloids, it does not categorize them into specific types.

5. **Classification Based on Interaction Between Phases**:
- Colloids can also be classified based on the interaction between the dispersed phase and the dispersion medium.
- This includes considering the physical states of both phases (solid, liquid, gas).
- Hence, this is also a valid criterion for classification.

### Conclusion:
The classification of colloidal systems is not based on **surface tension value**.