Which one of the followings is correctly matched ? 

Options

A. Emulsion - Curd
B. Foam-Mist
C. Aerosol-Smoke
D. Solid-Cake

Answer

To solve the question of which one of the following is correctly matched, we need to analyze the types of colloids and their corresponding examples. Here’s a step-by-step breakdown:

### Step 1: Understand the Types of Colloids
Colloids can be classified based on the state of their dispersed phase and dispersion medium. The main types include:
- **Emulsion**: Dispersed phase (liquid) + Dispersion medium (liquid)
- **Foam**: Dispersed phase (gas) + Dispersion medium (liquid)
- **Aerosol**: Dispersed phase (solid or liquid) + Dispersion medium (gas)
- **Solid sol**: Dispersed phase (solid) + Dispersion medium (solid)

### Step 2: Analyze Each Option
Now, let's evaluate the options provided in the question:

1. **Emulsion**: This is when both the dispersed phase and the dispersion medium are liquids. Examples include milk and cream. This option is not correctly matched if it refers to a solid or gas.

2. **Foam**: This is when the dispersed phase is gas and the dispersion medium is liquid. Examples include whipped cream. This option is also not correctly matched if it refers to a solid or gas.

3. **Aerosol**: This is when the dispersed phase is solid (or liquid) and the dispersion medium is gas. Examples include smoke and dust. This option is correctly matched since smoke is indeed an aerosol.

4. **Solid sol**: This is when both the dispersed phase and the dispersion medium are solid. Examples include gemstones. This option is not correctly matched if it refers to a liquid or gas.

### Step 3: Identify the Correct Match
From the analysis, the only option that is correctly matched is the **Aerosol**, which includes **smoke** as an example.

### Conclusion
The correct answer is **Aerosol - Smoke**.

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