Which of these materials is used to coat the iron metal to prevent it from rusting?

Options

A. Potassium
B. Calcium
C. Sodium
D. Zinc

Answer

To determine which material is used to coat iron metal to prevent it from rusting, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Rusting**:
- Rusting is a chemical process where iron reacts with oxygen and moisture in the environment, forming iron oxide (rust). To prevent this, a protective coating is often applied to iron.

2. **Identifying Coating Materials**:
- The question provides four options: potassium, calcium, sodium, and zinc. We need to analyze which of these materials can be used for coating iron.

3. **Analyzing the Options**:
- Potassium, calcium, and sodium are all alkali metals (S block metals). These metals are highly reactive and are not typically used for coating because they can easily react with moisture and air.
- Zinc, on the other hand, is a D block metal. It is commonly used in a process called electroplating to coat iron.

4. **Understanding Electroplating**:
- Electroplating is a method where a metal is deposited onto a surface using electrical energy. In this case, zinc can be electroplated onto iron to provide a protective layer.

5. **Conclusion**:
- Among the given options, zinc is the most suitable material for coating iron to prevent rusting. Therefore, the correct answer is **zinc**.

### Final Answer:
**Zinc** is used to coat iron metal to prevent it from rusting.

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