Assertion (A): `SF_(6)` molecule is unstable.
Reason (R): A stable molecule must have 8 electrons around the central atom. i.e. octet rule should be satisfied.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation
of the assertion.
B. If both Assertion & Reason are true but the reason is not the correct
explanation of the assertion.
C. If Assertion is true statement but Reason is false.
D. If both Assertion and Reason are false statements.

Answer

To solve the assertion and reason question regarding the stability of the `SF_(6)` molecule, we will analyze both the assertion and the reason step by step.

### Step 1: Understand the Assertion
The assertion states that the `SF_(6)` molecule is unstable.

**Hint:** Consider the definition of stability in chemical compounds and whether `SF_(6)` fits this definition.

### Step 2: Analyze the Reason
The reason provided states that a stable molecule must have 8 electrons around the central atom, implying that the octet rule should be satisfied.

**Hint:** Recall the octet rule and its exceptions, especially for elements in the third period and beyond.

### Step 3: Determine the Lewis Structure of `SF_(6)`
- **Sulfur (S)** has an atomic number of 16, with an electron configuration of `1s² 2s² 2p⁶ 3s² 3p⁴`. This means it has 6 electrons in its outermost shell.
- **Fluorine (F)** has an atomic number of 9, with an electron configuration of `1s² 2s² 2p⁵`. This means it has 7 electrons in its outermost shell.

In `SF_(6)`, sulfur is the central atom surrounded by 6 fluorine atoms. Each fluorine atom requires one electron to complete its octet, which it obtains by forming a single bond with sulfur.

### Step 4: Count the Electrons Around Sulfur
In `SF_(6)`, sulfur forms 6 bonds with 6 fluorine atoms:
- Sulfur shares 6 electrons (one with each fluorine), resulting in 12 electrons around sulfur (6 from the bonds).
- This configuration is known as an "expanded octet," which is possible for elements in the third period and beyond, like sulfur.

**Hint:** Remember that the octet rule is not a strict rule for all elements, especially those that can accommodate more than 8 electrons.

### Step 5: Conclusion on Stability
Despite having 12 electrons around sulfur, `SF_(6)` is a stable molecule. The assertion that `SF_(6)` is unstable is incorrect.

### Step 6: Conclusion on the Reason
The reason that a stable molecule must have 8 electrons around the central atom is also incorrect, as it does not account for the expanded octet that can occur in certain molecules.

### Final Conclusion
Both the assertion (A) and the reason (R) are false. Therefore, the correct answer is that both statements are incorrect.

**Final Answer:** Both assertion and reason are false.