Helium is used in balloons in place of hydrogen because it is

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

Explain the value of electron gain enthalpy of noble gases. Give reasons for your answer.

Complete hydrolysis of $XeF_6$ gives $HF$ along with compound $X$. The hybridisation in $X$ is

What is the correct order of occurrence (\% by weight) in air of $Ne, Ar$ and $Kr$?

Match the Xenon compounds in Column-$I$ with their structures in Column-$II$ and assign the correct code.

Column-$I$	Column-$II$
$(a) XeF_{4}$	$(i) \text{Pyramidal}$
$(b) XeF_{6}$	$(ii) \text{Square planar}$
$(c) XeOF_{4}$	$(iii) \text{Distorted octahedral}$
$(d) XeO_{3}$	$(iv) \text{Square pyramidal}$

Code: $(a) \quad (b) \quad (c) \quad (d)$