Hybridization of \(\mathrm{Si}-\mathrm{s} p^{3},\)     bond angle \(=109\,^o28'\)

\(\angle Cl-\text{N}-\text{Cl}\) in \(NCl_3\) is greater than \(\angle \text{Cl}-\text{P}-\text{Cl}\) in \(\mathrm{PCl}_{3}\) because partidpation of \(s-\) orbital in the hybridization decreases from \(NCl_3\) to \(PCl_3\)

Figure \((2)\)

\(\angle \text{Cl}-\text{P}-\text{Cl}\) in \(\text{PC}{{\text{l}}_{3}}>\angle \text{H}-\text{Sb}-\text{H}\) in \(\mathrm{SbH}_{3},\) as in \(\mathrm{SbH}_{3}\), bond pairs are formed by overlapping of almost pure \(p-\) orbitals.

\(\angle \text{H}-\text{Sb}-\text{H}\) in \(\text{Sb}{{\text{H}}_{3}}<\angle \text{H}-\text{Te}-\text{H}\) in \(\mathrm{H}_{2}Te\) because two lone pairs are present on \(Te\) while at \(\mathrm{Sb}\) there is one lone pair.