$XeF_6$ on hydrolysis produces

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. . . . . .

Monazite is a source of

Argon was discovered by

Which of the following xenon compound has a structure similar to chlorine pentafluoride $(ClF_5)$?

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