Which of the following is not a colloid?

Options

A. Chlorophyll
B. Smoke
C. Ruby glass
D. Milk

Answer

To determine which of the following is not a colloid, we need to understand the definition and characteristics of colloids. A colloid is a heterogeneous mixture consisting of two phases: the dispersed phase and the dispersion medium.

Let's analyze the options provided:

1. **Chlorophyll**: Chlorophyll is a pigment found in plants, primarily composed of a complex of magnesium. It is a pure component and does not consist of two distinct phases. Therefore, chlorophyll is not a colloid.

2. **Smoke**: Smoke is an aerosol, which consists of solid particles dispersed in air. This fits the definition of a colloid, as it has a dispersed phase (solid particles) and a dispersion medium (air).

3. **Ruby glass**: Ruby glass contains solid particles that are dispersed in a solid medium. This also qualifies as a colloid, specifically a solid-solid colloid.

4. **Milk**: Milk is an emulsion, which is a type of colloid where fat droplets are dispersed in water. It also fits the criteria for being a colloid.

Based on this analysis, the only option that does not qualify as a colloid is:

**Answer: Chlorophyll**