In the following questions, a statement of assertion (A) is followed by a statement of reason (R )
A : `N_(2)` is more stable than `N_(2)^(+)` .
R : Bond order of `N_(2)` is 3 while `N_(2)^(+)` is 2.5.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements , then mark (4).

Answer

To solve the question, we need to analyze the assertion (A) and the reason (R) provided:

**Assertion (A):** \( N_2 \) is more stable than \( N_2^+ \).

**Reason (R):** The bond order of \( N_2 \) is 3 while that of \( N_2^+ \) is 2.5.

### Step-by-Step Solution:

1. **Understanding Bond Order:**
- The bond order is a measure of the stability of a bond between two atoms. It is calculated using the formula:
\[ \text{Bond Order} = \frac{1}{2} \left( \text{Number of electrons in bonding orbitals} - \text{Number of electrons in antibonding orbitals} \right) \]

2. **Electronic Configuration of \( N_2 \):**
- The electronic configuration of \( N_2 \) can be derived from Molecular Orbital Theory (MOT). For \( N_2 \) (which has 14 electrons), the configuration is:
\[ \sigma_{1s}^2 \sigma_{1s}^*^2 \sigma_{2s}^2 \sigma_{2s}^*^2 \pi_{2p_x}^2 \pi_{2p_y}^2 \sigma_{2p_z}^2 \]
- In this configuration, the bonding orbitals are filled with 10 electrons (2 from \( \sigma_{1s} \), 2 from \( \sigma_{2s} \), 4 from \( \pi_{2p_x} \) and \( \pi_{2p_y} \), and 2 from \( \sigma_{2p_z} \)), while the antibonding orbitals have 4 electrons.

3. **Calculating Bond Order for \( N_2 \):**
- Using the bond order formula:
\[ \text{Bond Order of } N_2 = \frac{1}{2} (10 - 4) = \frac{6}{2} = 3 \]

4. **Electronic Configuration of \( N_2^+ \):**
- For \( N_2^+ \), one electron is removed from the bonding orbitals. The configuration now becomes:
\[ \sigma_{1s}^2 \sigma_{1s}^*^2 \sigma_{2s}^2 \sigma_{2s}^*^2 \pi_{2p_x}^2 \pi_{2p_y}^2 \sigma_{2p_z}^1 \]
- Here, the bonding orbitals have 9 electrons and the antibonding orbitals still have 4 electrons.

5. **Calculating Bond Order for \( N_2^+ \):**
- Using the bond order formula:
\[ \text{Bond Order of } N_2^+ = \frac{1}{2} (9 - 4) = \frac{5}{2} = 2.5 \]

6. **Comparing Stability:**
- Since the bond order of \( N_2 \) is 3 and that of \( N_2^+ \) is 2.5, we conclude that \( N_2 \) is indeed more stable than \( N_2^+ \).

7. **Conclusion:**
- Both the assertion (A) and the reason (R) are true, and the reason correctly explains the assertion. Therefore, the correct answer is that both statements are true and the reason is the correct explanation for the assertion.

### Final Answer:
Both assertion and reason are true, and the reason is the correct explanation of the assertion.