Which of the following is not a colloid ?

Options

A. Foam
B. Cloud
C. Rooh Afza syrup
D. Egg

Answer

To determine which of the following is not a colloid, we need to understand what a colloid is and examine the given options.

### Step-by-Step Solution:

1. **Understanding Colloids**: A colloid is a mixture where very small particles of one substance are evenly distributed throughout another substance. These particles do not settle out over time and cannot be separated by ordinary filtration.

2. **Identifying the Options**: The options provided in the question are:
- Foam
- Cloud
- Rooh Afza syrup
- Egg

3. **Analyzing Each Option**:
- **Foam**: This is a colloid where gas bubbles are dispersed in a liquid or solid. For example, whipped cream is a foam.
- **Cloud**: Clouds are also colloids, consisting of tiny water droplets or ice crystals suspended in the air.
- **Rooh Afza Syrup**: This is a homogeneous mixture of the syrup in water. It does not have the characteristics of a colloid as the components are completely dissolved and do not form a dispersed phase.
- **Egg**: An egg can be considered a colloid, as it contains proteins and water, where the proteins are dispersed in the water.

4. **Conclusion**: Among the options, Rooh Afza syrup is not a colloid because it is a homogeneous mixture, while the others (foam, cloud, and egg) are colloids.

### Final Answer:
The correct answer is **Rooh Afza syrup** (Option 3) is not a colloid.

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