In which of the following compounds resonance does not occurs :

(a) ${\mathrm{H}}_2\mathrm{O}$        (b) ${\mathrm{SiO}}_2$            (c) ${\mathrm{SO}}_3$         (d) ${\mathrm{CO}}_2$

The above compound represents hydrogen azide, the bond orders of bonds $\left(\mathrm{I}\right)$ and $\left(\mathrm{II}\right)$ are:

Resonance in carbonate ion $\left({\mathrm{CO}}_3^{2-}\right)$ is

Which of the following is true?

The molecule/molecules that has/have delocalised lone pair(s) of electrons is/are

Find out the correct order of ionic character in the following molecules

$\left(\mathrm{i}\right) {\mathrm{SO}}_2$     $\left(\mathrm{ii}\right) {\mathrm{K}}_2\mathrm{O}$     $\left(\mathrm{iii}\right) {\mathrm{N}}_2$    $\left(\mathrm{iv}\right) \mathrm{LiF}$

Give a reason for the following:

Ionic compounds have a high melting point.