The scattering of light by colloidal particles is known as tyndal effect. in a true solution the solute particle are so small that they cannot scatter light falling on them.
The components of colloidal solution are the dispersion medium.

Understanding the Tyndall Effect
The Tyndall Effect is a phenomenon that occurs when light is scattered by particles in a colloid or very fine suspension. This scattering makes the path of the light visible, allowing us to see the beam.
Examples of the Tyndall Effect
- Fog: In foggy conditions, tiny water droplets scatter light, making beams of light visible.
- Milk: When light passes through milk, it appears to scatter, demonstrating the Tyndall effect due to the fat and protein particles present.
Is Matter Around Us Pure?
The matter around us can be classified as pure substances or mixtures.
Pure Substances
- Definition: A pure substance consists of only one type of particle, either an element or a compound.
- Examples: Distilled water, gold, and sodium chloride (table salt) are pure substances as they have consistent properties and composition.
Mixtures
- Definition: Mixtures contain two or more different substances that retain their individual properties.
- Types:
- Homogeneous Mixtures: These have a uniform composition, such as air or saltwater.
- Heterogeneous Mixtures: These have non-uniform composition, like sand in water or salad.
Conclusion
Understanding the Tyndall Effect not only helps in identifying colloids but also emphasizes the distinction between pure substances and mixtures in our surroundings. The study of these concepts is essential for grasping the nature of matter.