Which of the following noble gases is lighter than air?

Total number of lone pairs of electrons in $XeOF_4$ is

The number of $p \pi-d \pi$ 'pi' bonds present in $XeO_3$ and $XeO_4$ molecules,respectively,are

Match List-$I$ with List-$II$ and select the correct answer using the codes given below the lists:

List-$I$	List-$II$
$(A) \ XeF_4$	$(1) \ \text{Distorted octahedral}$
$(B) \ XeF_6$	$(2) \ \text{Tetrahedral}$
$(C) \ XeO_3$	$(3) \ \text{Square planar}$
$(D) \ XeO_4$	$(4) \ \text{Pyramidal}$

Give the formula and describe the structure of a noble gas species which is isostructural with:
$(i)$ $ICl_{4}^{-}$
$(ii)$ $IBr_{2}^{-}$
$(iii)$ $BrO_{3}^{-}$

Which of the following inert gases participates in chemical reactions?