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 first need to understand what a colloid is. A colloid is a homogeneous mixture where one substance is dispersed evenly throughout another. This mixture consists of large molecules or ultramicroscopic particles that do not settle out over time. Colloids can be found in various forms, such as gels, emulsions, and foams.

Now, let's analyze the options given:

1. **Chlorophyll**: This is a pigment found in plants, primarily responsible for the absorption of light during photosynthesis. It is not a colloid as it does not consist of dispersed particles in a continuous medium.

2. **Smoke**: Smoke is a colloid consisting of solid particles dispersed in a gas. It is a well-known example of a colloidal system.

3. **Ruby Glass**: Ruby glass is a type of glass that contains solid particles (gold or silver) dispersed in a solid matrix. This also qualifies as a colloid.

4. **Milk**: Milk is an emulsion, which is a colloid of liquid droplets dispersed in another liquid. It is a classic example of a colloidal system.

After analyzing all the options, we can conclude that:

- **Chlorophyll** is not a colloid, while smoke, ruby glass, and milk are all colloids.

Therefore, the answer to the question "Which of the following is not a colloid?" is **Chlorophyll**.