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 of which metal is used for the extraction of gold (Au) and silver (Ag), as well as for galvanization of iron objects, we can break down the solution into the following steps:

### Step 1: Identify the metals used in extraction
- The first part of the question asks about the extraction of gold and silver. In metallurgy, certain metals are used as reducing agents to extract precious metals from their ores.

### Step 2: Determine the reducing agent
- The metal that is commonly used as a reducing agent for the extraction of gold and silver is zinc (Zn). Zinc effectively reduces the metal ions of gold and silver to their elemental forms.

### Step 3: Understand galvanization
- The second part of the question involves galvanization. Galvanization is the process of applying a protective zinc coating to iron or steel to prevent rusting.

### Step 4: Explain the reason for using zinc in galvanization
- Zinc is more electropositive than iron, meaning it can easily lose electrons and form ions. This property allows zinc to protect iron from corrosion by acting as a sacrificial anode. When iron is coated with zinc, the zinc will corrode first, thus protecting the underlying iron.

### Conclusion
- Therefore, the metal that is used for both the extraction of gold and silver and for the galvanization of iron objects is **zinc (Zn)**.

### Final Answer
- The answer to the question is **Zinc (Zn)**.

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