Which metal is used for extraction of `Au` and `Ag` and also for galvanisation of iron objects ?

Options

A. Mg
B. Zn
C. Cr
D. Co

Answer

To solve the question, we need to identify the metal that is used for both the extraction of gold (Au) and silver (Ag) and for the galvanization of iron objects.

### Step-by-Step Solution:

1. **Understanding the Extraction of Gold and Silver**:
- Gold and silver are often extracted from their ores using a reducing agent. A reducing agent is a substance that donates electrons to another substance, reducing its oxidation state.
- In the case of gold and silver extraction, zinc (Zn) is commonly used as a reducing agent.

2. **Identifying the Process of Galvanization**:
- Galvanization is a process used to protect iron and steel from rusting. This is typically done by coating the iron with a layer of zinc.
- Zinc is chosen for galvanization because it is more electropositive than iron, meaning it will corrode preferentially and protect the underlying iron from rusting.

3. **Conclusion**:
- Since zinc is used both as a reducing agent in the extraction of gold and silver and for the galvanization of iron objects, we can conclude that the answer to the question is zinc (Zn).

### Final Answer:
The metal used for the extraction of gold (Au) and silver (Ag) and for the galvanization of iron objects is **Zinc (Zn)**.

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