Which metal is protected by layer of its own oxide ?

Options

A. Gold
B. Aluminium
C. Copper
D. Iron

Answer

To determine which metal is protected by a layer of its own oxide, we can analyze the properties of the given metals: Gold, Aluminium, Copper, and Iron.

### Step 1: Analyze the metals
- **Gold**: Gold is a noble metal and is least reactive. It does not readily form oxides and does not corrode easily. Therefore, it does not rely on an oxide layer for protection.

- **Aluminium**: Aluminium is a highly reactive metal that reacts readily with oxygen in the air to form Aluminium Oxide (Al2O3). This oxide layer forms a thin, passive barrier that protects the underlying metal from further oxidation and corrosion.

- **Copper**: Copper does form an oxide layer, but it is not as protective as Aluminium Oxide. Copper can still corrode under certain conditions, especially in the presence of moisture and acidic environments.

- **Iron**: Iron reacts with oxygen to form iron oxide (rust), but this layer is not protective. Rust can flake off, exposing fresh iron to further corrosion.

### Step 2: Conclusion
Based on the analysis, Aluminium is the metal that is protected by a layer of its own oxide, Aluminium Oxide (Al2O3), which prevents further corrosion.

### Final Answer
The metal that is protected by a layer of its own oxide is **Aluminium**.

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