Which of the following molecules contains both ionic and covalent bonds?

$S-O$ bond length is maximum in

Consider the following statements:
$A$. $NF_3$ molecule has a trigonal planar structure.
$B$. Bond length of $N_2$ is shorter than $O_2$.
$C$. Isoelectronic molecules or ions have identical bond order.
$D$. Dipole moment of $H_2S$ is higher than that of water molecule.
Choose the correct answer from the options below:

Which of the following does not undergo Lewis acid-base reaction?

The number of molecules or ions from the following,which do not have an odd number of electrons are $...............$.
$A. NO_2$ $B. ICl_4^{-}$ $C. BrF_3$ $D. ClO_2$ $E. NO_2^{+}$ $F. NO$

Consider the following molecules: $(I)$ $POF_3$,$(II)$ $SOF_4$,$(III)$ $IOF_5$. On moving from $(I)$ to $(III)$,which of the following changes is $NOT$ observed?