Which one of the following does not exist ?
`(i) XeOF_(4) (ii) NeF_(2) (iii) XeF_(2) (iv) XeF_(6)`.

Explanation

The sum of first and second ionization enthalpies of Ne are much higher than those of Xe. As a result, `F_(2)` can oxidise Xe to `Xe^(2+)` but cannot oxidise Ne to `Ne^(2+)`. In other words, `NeF_(2)` does not exist. In contrast, all the xenon fluorides `(XeF_(4) and XeF_(6))` and xenon oxyfluoride `(XeOF_(4))` do exist.