Explain colloid with examples?

A colloid is a type of mixture in which one substance is evenly spread throughout another, and the particles are larger than in a solution but smaller than in a suspension. Examples of colloids are milk, fog, butter, and paint.

In a colloid, the particles do not settle down on standing, and they cannot be separated by simple filtration. The size of colloidal particles is usually between 1 nanometer and 1000 nanometers. Colloids appear uniform but are heterogeneous mixtures at the microscopic level.

Types of Colloids with Examples

• Sol: Solid in liquid (e.g., paint, ink).
• Gel: Liquid in solid (e.g., jelly, cheese).
• Emulsion: Liquid in liquid (e.g., milk, cream).
• Aerosol: Solid or liquid in gas (e.g., fog, smoke).

Colloids show a special effect called the Tyndall effect, where light scatters when passed through a colloid. This helps to distinguish colloids from true solutions.