Define the term 'Tyndall effect'.

Explanation

**Step-by-Step Solution:**

1. **Definition of Tyndall Effect:**
The Tyndall effect refers to the phenomenon where light is scattered by particles in a colloid or in very fine suspensions.

2. **Explanation of the Phenomenon:**
When a beam of light passes through a colloidal solution, the colloidal particles scatter the light in different directions. This scattering makes the path of the light beam visible.

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