The number of $Cl=O$ bonds in perchloric acid is:

Which of the following structures is the most preferred and hence of lowest energy for $SO_3$?

Which of the following is the correct decreasing order of bond angles?

Fill in the blanks:
$(i)$ In $1927$,Heitler and London proposed the ........ theory.
$(ii)$ The ${\rm{ClF}}_3$ molecule has a .... shape.
$(iii)$ The number of bonding pairs in ions with a square planar shape is .......... .
$(iv)$ The value of the dipole moment in ${\rm{HBr}}$ is .......... .

The ionic bond is absent in

Match the following species in List-$I$ with the number of lone pairs in List-$II$.

List-$I$ (Species)	List-$II$ (Number of lone pairs)
$A. \ CH_3COCH_3$	$I. \ 2$
$B. \ CH_3CO^+$	$II. \ 0$
$C. \ CH_3CH_2^+$	$III. \ 1$
	$IV. \ 3$