Assertion : Both `BF_(3) and PF_(5)` do not obey octet rule.
Reason : Both are electron deficient molecules.

Options

A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.

Explanation

To analyze the assertion and reason provided in the question, we will break it down step by step.

### Step 1: Understanding the Assertion
The assertion states that both BF₃ (Boron Trifluoride) and PF₅ (Phosphorus Pentafluoride) do not obey the octet rule.

**Hint:** Recall that the octet rule states that atoms tend to form bonds until they are surrounded by eight valence electrons.

### Step 2: Analyzing BF₃
- BF₃ has Boron (B) at the center with three Fluorine (F) atoms bonded to it.
- Boron has 3 valence electrons and forms three bonds with Fluorine atoms.
- Each Fluorine atom contributes 1 electron to the bond, giving a total of 6 electrons around Boron (3 from B and 3 from F).
- Since Boron has only 6 electrons in its valence shell, it does not complete the octet.

**Conclusion for BF₃:** It is an electron-deficient molecule.

**Hint:** Count the total number of electrons around Boron to confirm if it meets the octet rule.

### Step 3: Analyzing PF₅
- PF₅ has Phosphorus (P) at the center with five Fluorine (F) atoms bonded to it.
- Phosphorus has 5 valence electrons and forms five bonds with Fluorine atoms.
- Each Fluorine atom contributes 1 electron to the bond, giving a total of 10 electrons around Phosphorus (5 from P and 5 from F).
- Since Phosphorus has more than 8 electrons in its valence shell, it does not follow the octet rule.

**Conclusion for PF₅:** It is an electron-rich molecule.

**Hint:** Check the total number of electrons around Phosphorus to see if it exceeds the octet.

### Step 4: Evaluating the Reason
The reason states that both BF₃ and PF₅ are electron-deficient molecules.
- While BF₃ is indeed electron-deficient, PF₅ is not; it is electron-rich due to having 10 electrons in its valence shell.

**Conclusion for the Reason:** The reason is incorrect because it inaccurately describes PF₅.

### Final Conclusion
- The assertion is correct: Both BF₃ and PF₅ do not obey the octet rule.
- The reason is incorrect: Only BF₃ is electron-deficient, while PF₅ is electron-rich.

### Final Answer
The correct option is that the assertion is correct, but the reason is wrong.

---