Rusting of iron involves

Options

A. oxidation
B. reduction
C. decompositions
D. displacement

Explanation

**Step-by-Step Solution:**

1. **Understanding Rusting**: Rusting of iron is a chemical process that occurs when iron reacts with moisture and oxygen in the environment. This process leads to the formation of rust, which is primarily composed of iron(III) oxide (Fe2O3) and iron(III) hydroxide (Fe(OH)3).

2. **Identifying the Reaction Type**: Rusting is classified as an oxidation reaction. In this context, oxidation refers to the loss of electrons by iron when it reacts with oxygen.

3. **Chemical Equation**: The chemical reaction can be represented as:
\[ 4Fe + 6H2O + 3O2 \rightarrow 4Fe(OH)3 \]
This shows that iron (Fe) reacts with water (H2O) and oxygen (O2) to form iron(III) hydroxide (Fe(OH)3), which eventually decomposes to form rust.

4. **Final Product**: The rust formed can be represented as hydrated iron(III) oxide, which is commonly known as rust. The overall process can be summarized as:
\[ 4Fe(OH)3 \rightarrow 2Fe2O3 \cdot 3H2O \]
This indicates that rusting involves both oxidation and the formation of a hydrated compound.

5. **Conclusion**: Since rusting involves the reaction of iron with oxygen and water, resulting in the formation of rust through oxidation, the correct answer to the question "Rusting of iron involves" is **A: oxidation**.

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