Correct Option
The correct option isThe scattering of a beam of light by colloidal particles.
Explanation
The Tyndall effect is an optical phenomenon observed in colloidal solutions and fine suspensions. It involves the scattering of light by particles that are large enough to interact with light waves but small enough to remain suspended. This effect is the primary method used to distinguish a true solution from a colloid.
Option Analysis:
- The precipitation of solute particles in a saturated solution. is Incorrect: The precipitation of solute particles in a saturated solution refers to crystallization or precipitation. This occurs when the solution can no longer hold the solute, causing it to separate as a solid.
- The scattering of a beam of light by colloidal particles. is Correct: The Tyndall effect is defined as the scattering of a beam of light by colloidal particles. When light passes through a colloid (e.g., milk or fog), the suspended particles scatter the light in all directions, making the path of the beam visible. In contrast, particles in a true solution are too small to scatter light, so the path remains invisible.
- The separation of components based on density. is Incorrect: The separation of components based on density is the principle underlying centrifugation or sedimentation, not the Tyndall effect.
- The movement of solvent molecules through a semi-permeable membrane. is Incorrect: The movement of solvent molecules through a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration is known as Osmosis.
Key Takeaway:
The Tyndall effect specifically refers to the scattering of light by colloidal particles, rendering the path of the light beam visible.