The ion which is not tetrahedral in shape is:

Consider the following statements:

${\mathrm{S}}_1$: ${\mathrm{N}}_2{\mathrm{H}}_4$ is pyramidal about each $\mathrm{N}$ atom.

${\mathrm{S}}_2$: ${\mathrm{NH}}_2\mathrm{OH}$ is pyramidal about the $\mathrm{N}$ atom and bent about the $\mathrm{O}$ atom.

${\mathrm{S}}_3$: ${\mathrm{CH}}_3\mathrm{COCl}$ is trigonal about the carbon atom (attached to $\mathrm{O}$ and $\mathrm{Cl}$).

Out of these, select the correct one.

Consider the following statements:

${\mathrm{S}}_1$: Fluorine does not form any polyhalide because it does not have $\mathrm{d}$-orbitals in the valence shell.

${\mathrm{S}}_2$: In ${\mathrm{CIF}}_3$, the three lone pairs of electrons occupy the equatorial position.

${\mathrm{S}}_3$: In ${\mathrm{B}}_2$ and ${\mathrm{N}}_2$ molecules, mixing of $\mathrm{s}$- and $\mathrm{p}$-atomic orbitals takes place.

Of these statements: