The noble gases which do not form any clatherate

Options

A. Xe
B. Kr
C. He
D. Ar

Explanation

To determine which noble gas does not form any clathrate, we need to analyze the properties of the noble gases provided: xenon, krypton, helium, and argon.

### Step-by-Step Solution:

1. **Understanding Clathrate Formation**:
- Clathrates are compounds where gas molecules are trapped within a lattice of another substance. For a noble gas to form a clathrate, it must fit into the voids of the host lattice structure.

2. **Identifying the Noble Gases**:
- The noble gases in question are:
- Helium (He)
- Argon (Ar)
- Krypton (Kr)
- Xenon (Xe)

3. **Analyzing Atomic Sizes**:
- The atomic size of noble gases increases as we move down the group in the periodic table. Therefore, their sizes are as follows:
- Helium (smallest)
- Argon
- Krypton
- Xenon (largest)

4. **Determining Clathrate Formation Ability**:
- For a noble gas to form a clathrate, it needs to fit into the voids of the host lattice.
- Helium, being the smallest noble gas, has a size that is too small to fit into the voids of most host lattices.

5. **Conclusion**:
- Since helium cannot fit into the voids, it does not form any clathrate compounds. Therefore, the answer to the question is **Helium (He)**.

### Final Answer:
The noble gas which does not form any clathrate is **Helium (He)**.