It is because of inability of ns² electrons of the valence shell to participate in bonding that

Match the interhalogen compounds of column-I with the geometry in column-II and assign the correct code.

Column $${\rm I}$$			Column $${\rm I}$$$${\rm I}$$
(A)	XX'		(i)	T-shape
(B)	XX'3		(ii)	Pentagonal bipyramidal
(C)	XX'5		(iii)	Linear
(D)	XX'7		(iv)	Square pyramidal
			(v)	Tetrahedral

The correct increasing order of basic strength for the following compounds is

Name the gas that can readily decolourise acidified KMnO₄ solution.