_________ is the process in which iron reacts with oxygen and water vapours present in air and turns into a reddish-brown substance.

Options

A. Rusting
B. Electroplating
C. Vulcanization
D. Galvanization

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Process**: The question asks about a specific process where iron reacts with oxygen and water vapors in the air. This process leads to the formation of a reddish-brown substance.

2. **Identifying the Substance**: The reddish-brown substance formed from this reaction is commonly known as rust.

3. **Chemical Reaction**: The chemical reaction that describes the rusting process can be represented as:
\[ 4 \text{Fe} + 3 \text{O}_2 + 6 \text{H}_2\text{O} \rightarrow 4 \text{Fe(OH)}_3 \]
This can also be simplified to:
\[ 2 \text{Fe}_2\text{O}_3 \cdot 3 \text{H}_2\text{O} \]
Here, \(\text{Fe}_2\text{O}_3\) represents iron(III) oxide, which is a major component of rust.

4. **Conclusion**: Based on the information provided, the process in which iron reacts with oxygen and water vapor to form rust is called **rusting**.

5. **Final Answer**: The correct answer to the question is **rusting**.

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