What is the atomic state of noble gases?

$XeF_6$ dissolves in anhydrous $HF$ to give a good conducting solution which contains:

$XeF_6$ on partial hydrolysis with water produces a compound '$X$'. The same compound '$X$' is formed when $XeF_6$ reacts with silica. The compound '$X$' is

Which of the following is not obtained by the direct reaction of constituent elements?

Xenon reacts with fluorine at $873 \ K$ and $7 \ bar$ to form $XeF_4$. In this reaction, the ratio of xenon and fluorine required is

The structure of $XeOF_4$ is