When treated with conc. `HNO_(3)` aluminium is rendered `"………….."` due to the formation of protective layer of its `"………….."` on the surface of the metal.

Answer

To solve the question, we need to identify the two key components that are being asked about when aluminum is treated with concentrated nitric acid (HNO3).

### Step-by-Step Solution:

1. **Understanding the Reaction**: When aluminum (Al) is treated with concentrated nitric acid (HNO3), it undergoes a chemical reaction. This reaction is significant because it leads to a change in the reactivity of aluminum.

2. **Formation of Passive Layer**: During the reaction, aluminum reacts with nitric acid, and as a result, a protective layer is formed on the surface of the aluminum metal. This layer is crucial because it prevents further reaction of aluminum with the acid.

3. **Identifying the Passive Layer**: The protective layer that forms on the surface of aluminum is primarily aluminum oxide (Al2O3). This oxide layer is very thin but effectively protects the underlying aluminum from further corrosion or reaction.

4. **Conclusion**: Therefore, when aluminum is treated with concentrated HNO3, it is rendered "passive" due to the formation of a protective layer of its "oxide" on the surface of the metal.

### Final Answer:
When treated with conc. `HNO3`, aluminum is rendered **"passive"** due to the formation of a protective layer of its **"oxide"** on the surface of the metal.

---