Which one of the following does not exist ?
(i) `XeOF_4` (ii) `NeF_2` (iii) `XeF_2` (iv) `XeF_6`

Explanation

To determine which of the following compounds does not exist, we need to analyze each option based on the properties of the elements involved and their ability to form compounds.

### Step-by-Step Solution:

1. **Understanding the Elements**:
- **Xenon (Xe)** is a noble gas that can form compounds due to the presence of vacant d-orbitals.
- **Neon (Ne)** is also a noble gas but has a complete octet and lacks vacant d-orbitals.

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