Select the correct statement(s).

($\mathrm{I}$) Polarizability of ${\mathrm{S}}^{2-}$ is lower than ${\mathrm{Se}}^{2-}$
($\mathrm{II}$) Polarizability of ${\mathrm{S}}^{2-}$ is higher than ${\mathrm{Cl}}^{-}$
($\mathrm{III}$) Polarizability of ${\mathrm{S}}^{2-}$ is lower than ${\mathrm{P}}^{3-}$
($\mathrm{IV}$) Polarizability of ${\mathrm{O}}^{2-}$ is higher than ${\mathrm{S}}^{2-}$

1. ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CHO}$

2. ${\mathrm{CH}}_3\mathrm{CH}=\mathrm{CHCHO}$

3. ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CH}={\mathrm{CH}}_2$

The experimental value of the dipole moment of $\mathrm{HCl}$ is $1.03 \mathrm{D}$. The length of the $\mathrm{H}-\mathrm{Cl}$ bond is $1.275 \mathrm{\AA }$. The percentage ionic character in $\mathrm{HCl}$ is:

How many lone pairs are present in the given cation?

The geometry around how many carbon atoms is tetrahedral in the given structure?