A : `NaN_(3) and Na_(3)` N both are stable.
R : Na when reacted with atmospheric nitrogen at different temperature forms. Stable `NaN_(3) and Na_(3)N`

Options

A. If both Assertion & Reason are true and the reason is the correct explanantion of the assertion, then mark (1).
B. If both Assertion & Reason are true and the reason is the correct explanantion of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false. Them mark (3).
D. If both Assertion and reason are false statement, then mark (4).

Answer

To analyze the given assertion and reason, we will break down the statements step by step.

### Step 1: Understanding the Assertion
The assertion states that both NaN₃ (sodium azide) and Na₃N (sodium nitride) are stable compounds.

**Analysis**:
- Sodium azide (NaN₃) is indeed a known stable compound. It is used in various applications, including as a propellant in airbags.
- Sodium nitride (Na₃N) is less commonly discussed but is also considered stable under certain conditions.

### Step 2: Understanding the Reason
The reason provided states that sodium reacts with atmospheric nitrogen at different temperatures to form stable NaN₃ and Na₃N.

**Analysis**:
- Sodium does react with nitrogen, but the formation of NaN₃ and Na₃N occurs under specific conditions.
- NaN₃ can be formed through the reaction of sodium with nitrogen, but Na₃N is not typically formed in significant amounts under normal atmospheric conditions.

### Step 3: Evaluating the Truth of the Statements
- **Assertion (A)**: While NaN₃ is stable, Na₃N is not commonly recognized as a stable compound under standard conditions.
- **Reason (R)**: The statement about sodium reacting with nitrogen to form both compounds is misleading because Na₃N is not typically formed in practical scenarios.

### Conclusion
Given that the assertion is partially true (NaN₃ is stable, but Na₃N is not commonly recognized as stable) and the reason is misleading (not all reactions lead to stable compounds), we conclude that:

- **Assertion (A)** is not entirely correct.
- **Reason (R)** is also misleading.

Thus, the correct answer is that both the assertion and the reason are false.

### Final Answer
Both the assertion and the reason are false.

---