`SiO_(2)` is a:

Options

A. flux
B. gangue
C. slag
D. catalyst

Answer

To determine what `SiO_(2)` is, we need to analyze the options provided: flux, gang, slag, or catalyst.

### Step-by-Step Solution:

1. **Understanding `SiO_(2)`**:
- `SiO_(2)` is silicon dioxide, which is a compound made of silicon and oxygen.

2. **Identifying the Options**:
- **Flux**: A substance that helps remove impurities from ores during the extraction of metals.
- **Gang**: The term used for the impurities present in the ore itself.
- **Slag**: The waste material that is formed when impurities combine with flux during the smelting process.
- **Catalyst**: A substance that increases the rate of a chemical reaction without being consumed in the process.

3. **Analyzing `SiO_(2)`**:
- `SiO_(2)` is commonly used as a flux in metallurgy. It helps in the removal of impurities by forming slag when combined with them during the smelting process.

4. **Conclusion**:
- Since `SiO_(2)` acts as a flux in the extraction of metals, the correct answer is **flux**.

### Final Answer:
`SiO_(2)` is a **flux**.

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