Assertion(A) : `IE_(2)` of `Li` is the highest in the second period.
Reason (R ): `Li^(o+)` has noble gas i.e., `Ne` gas configuration.

Options

A. If both Assertion (A) and (R ) are correct and Reason (R ) is the
correct explanation of Assertion (A).
B. If both (A) and (R ) are correct but (R ) is not the correct
explanation for (A).
C. If (A) is correct but (R ) is not correct.
D. If (A) and (R ) are correct

Explanation

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

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that the second ionization energy (IE₂) of lithium (Li) is the highest in the second period.
- The second ionization energy refers to the energy required to remove the second electron from a gaseous atom after the first electron has already been removed.

2. **Analyzing the Ionization Energy of Lithium**:
- Lithium has the electronic configuration of 1s² 2s¹.
- When the first electron is removed (IE₁), lithium becomes Li⁺ with the configuration 1s², which is the same as helium (He).
- The removal of the second electron (IE₂) from Li⁺ (which has a stable noble gas configuration) requires significantly more energy because it is now removing an electron from a stable configuration.

3. **Conclusion on Assertion**:
- Since the second ionization energy of lithium is indeed the highest in the second period due to the stability of the He configuration after the first ionization, the assertion (A) is **correct**.

4. **Understanding the Reason (R)**:
- The reason states that Li⁺ has a noble gas configuration, specifically that of neon (Ne).
- However, after the removal of one electron, Li⁺ has the electronic configuration of 1s², which corresponds to helium (He), not neon (Ne).

5. **Conclusion on Reason**:
- Therefore, the reason (R) is **incorrect** because it incorrectly identifies the noble gas configuration of Li⁺.

6. **Final Evaluation**:
- Since the assertion (A) is correct and the reason (R) is incorrect, we conclude that the answer to the question is that the assertion is correct, but the reason is not correct.

### Final Answer:
Assertion (A) is correct, but Reason (R) is incorrect.

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