Assertion : `CaF_2` has been given the same fluorspar.
Reason : Solid `CaF_2` emits light when heated

Options

A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion
B. Both Assertion and Reason are true and Reason is not the correct explanation of Assertion
C. Assertion is true but Reason is false
D. Both Assertion and Reason are false

Answer

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

### Step 1: Analyze the Assertion
The assertion states that `CaF_2` (calcium fluoride) is known as fluorspar.

- **Explanation**: Calcium fluoride is indeed commonly referred to as fluorspar. It is a naturally occurring mineral that is primarily composed of calcium and fluorine. This name is widely accepted in the field of chemistry and mineralogy.

### Step 2: Analyze the Reason
The reason states that solid `CaF_2` emits light when heated.

- **Explanation**: Calcium fluoride does exhibit fluorescence; it can emit light when exposed to ultraviolet (UV) light. However, it does not necessarily emit light simply when heated. The emission of light is more specifically associated with its interaction with UV light rather than just heat.

### Step 3: Determine the Relationship
Now, we need to determine if the reason correctly explains the assertion.

- The assertion is true: `CaF_2` is indeed called fluorspar.
- The reason is also true in that `CaF_2` can emit light, but it does not serve as a correct explanation for why it is called fluorspar. The term "fluorspar" is derived from its fluorescent properties, but the reason provided does not accurately explain the assertion.

### Conclusion
Based on the analysis:
- Both the assertion and the reason are true.
- However, the reason does not correctly explain the assertion.

Thus, the correct answer is:
**Option B: Assertion and Reason are true. Reason is not the correct explanation of Assertion.**

---