A : Xe is the only element of group 18 which from compounds .
R : Xe does not form clatherates

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion , then mark (2)
C. If Assertion is true statement but Reason is false , then mark (3)
D. If both Assertion and Reason are false statements , then mark (4)

Answer

To solve the question regarding the assertion and reasoning about xenon (Xe) and its properties as a noble gas, we can break down the information step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states: "Xe is the only element of group 18 which forms compounds."
- Group 18 consists of noble gases, which are typically known for their lack of reactivity due to having a complete valence shell. However, xenon is known to form several compounds, such as xenon difluoride (XeF2), xenon tetrafluoride (XeF4), and xenon oxytetrafluoride (XeOF4).
- While xenon is the most well-known noble gas to form compounds, it is not the only one. Other noble gases like radon (Rn) can also form compounds under certain conditions. Therefore, the assertion is **false**.

2. **Understanding the Reasoning**:
- The reasoning states: "Xe does not form clathrates."
- Clathrates are complex structures that trap gas molecules within a cage-like framework, typically formed by water or other molecules.
- It is known that xenon can indeed form clathrate hydrates, where xenon gas is trapped within a lattice of water molecules. Therefore, the reasoning is also **false**.

3. **Conclusion**:
- Since both the assertion and the reasoning are false, the correct answer is that both are incorrect.

### Final Answer:
Both the assertion and the reasoning are false.