Why is a layer of zinc coated over iron?

Explanation

**Step-by-Step Solution:**

1. **Understanding Corrosion**: Corrosion is a natural process that occurs when metals react with moisture and oxygen in the environment. Iron, in particular, is prone to rusting when exposed to these elements.

**Hint**: Think about how metals react with water and air. What happens to iron when it is exposed to moisture?

2. **Introduction to Galvanization**: To protect iron from corrosion, a process called galvanization is used. This involves applying a protective layer of zinc over the iron surface.

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