Assertion : All forms `[AlF_(6)]^(3-)` but B does not form `[BF_(6)]^(3-)`.
Reason : B does not react with fluorine.

Options

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

Explanation

To solve the question, we need to analyze the assertion and reason provided:

### Step 1: Understanding the Assertion
The assertion states that "All forms [AlF6]^(3-) but B does not form [BF6]^(3-)."
- Here, we recognize that aluminum (Al) can form the complex ion [AlF6]^(3-) because it can expand its octet due to the presence of d orbitals.
- On the other hand, boron (B) does not form [BF6]^(3-) due to its inability to expand its octet.

### Step 2: Understanding the Reason
The reason states that "B does not react with fluorine."
- This statement is misleading. Boron does react with fluorine to form BF3, but it cannot form BF6^(3-) because it lacks the ability to expand its octet.

### Step 3: Evaluating the Relationship Between Assertion and Reason
- The assertion is true because aluminum can form [AlF6]^(3-) while boron cannot form [BF6]^(3-).
- The reason is false because boron does react with fluorine, but it only forms BF3.

### Conclusion
- Therefore, we conclude that the assertion is true, but the reason is false.

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

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