Why true solutions do not exhibit tyndall effect?

Answer

### Step-by-Step Solution

1. **Understanding Tyndall Effect**:
- The Tyndall effect refers to the scattering of light when it passes through a medium that contains small suspended particles. This scattering causes the light beam to become visible.

2. **Characteristics of True Solutions**:
- True solutions are homogeneous mixtures where the solute particles are completely dissolved in the solvent. The size of the solute particles in true solutions is typically less than 1 nanometer.

3. **Particle Size and Light Scattering**:
- For the Tyndall effect to occur, the particles in the medium must be large enough to scatter light. In true solutions, since the particle size is less than 1 nanometer, these particles are too small to scatter light effectively.

4. **Conclusion**:
- Because the particles in true solutions are smaller than the wavelength of visible light, they do not scatter light and therefore do not exhibit the Tyndall effect. In contrast, colloidal solutions, which contain larger particles (1 nanometer to 100 nanometers), can scatter light and thus show the Tyndall effect.

### Final Answer
True solutions do not exhibit the Tyndall effect because the size of their solute particles is less than 1 nanometer, which is too small to scatter light. In contrast, colloidal solutions contain larger particles that can scatter light, leading to the Tyndall effect.

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