Both ${\mathrm{CO}}_2$ and ${\mathrm{H}}_2\mathrm{O}$ contain polar covalent bonds but ${\mathrm{CO}}_2$ is nonpolar while ${\mathrm{H}}_2\mathrm{O}$ is polar because-

If the $\mathrm{z}$-axis is the molecular axis, then $\mathrm{\pi }$ $\mathrm{MOs}$ are formed by the overlap of-

$\left(\mathrm{i}\right)$ ${\mathrm{p}}_{\mathrm{z}}$ and ${\mathrm{p}}_{\mathrm{z}}$
$\left(\mathrm{ii}\right)$ ${\mathrm{p}}_{\mathrm{y}}$ and ${\mathrm{p}}_{\mathrm{y}}$
$\left(\mathrm{iii}\right)$ ${\mathrm{s}}_{\mathrm{z}}$ and ${\mathrm{p}}_{\mathrm{z}}$
$\left(\mathrm{iv}\right)$ ${\mathrm{p}}_{\mathrm{x}}$ and ${\mathrm{p}}_{\mathrm{x}}$

Which of the following contains $\mathrm{Co}$-ordinate and covalent bonds:-

$\left(\mathrm{a}\right)$ ${\mathrm{N}}_2{\mathrm{H}}_5^{+}$
$\left(\mathrm{b}\right)$ ${\mathrm{H}}_3{\mathrm{O}}^{+}$
$\left(\mathrm{с}\right)$ $\mathrm{HCl}$
$\left(\mathrm{d}\right)$ ${\mathrm{H}}_2\mathrm{O}$

Correct answer is :-

${\mathrm{NH}}_3+{\mathrm{H}}^{+}\to {\mathrm{NH}}_4^{+}$

One of the resonating structure of ${\mathrm{SO}}_4^{-2}$ is

Which set of formal charge on oxygen and bond order is correct