The element that can even diffuse through silica glass is

Which noble gas was discovered first in the sun and then on the earth?

What is the atomic state of noble gases?

$Xe_{(g)} + 2 F_{2(g)} \xrightarrow[7 \text{ bar }]{873 \text{ K}} XeF_{4(s)}$
The ratio of $Xe : F_2$ required in the above reaction is

Why does the following reaction occur?
$XeO_{6(aq)}^{4-} + 2F_{(aq)}^{-} + 6H_{(aq)}^{+} \to XeO_{3(g)} + F_{2(g)} + 3H_2O_{(l)}$
What conclusion about the compound $Na_4XeO_6$ (of which $XeO_6^{4-}$ is a part) can be drawn from the reaction?

Xenon $(VI)$ fluoride on complete hydrolysis gives an oxide of xenon '$O$'. The total number of $\sigma$ and $\pi$ bonds in '$O$' is