What is the percentage of $Argon$ in the air (in $\%$)?

The reaction of $Xe$ and $O_2F_2$ gives a $Xe$ compound $P$. The number of moles of $HF$ produced by the complete hydrolysis of $1 \ mol$ of $P$ is. . . . . .

$A$ xenon compound '$A$' upon partial hydrolysis gives $XeO_{2}F_{2}$. The number of lone pairs of electrons present in compound $A$ is ....... . (Round off to the nearest integer)

Identify the incorrect statement regarding the molecule $XeO_4$:

Assertion $(A)$: The boiling points of noble gases increase from $He$ to $Xe$.
Reason $(R)$: The interatomic van der Waals' attractive forces increase from $He$ to $Xe$.
The correct answer is:

The noble gas compound prepared by Bartlett was