Maximum number of atom(s) in ${\mathrm{I}}_2{\mathrm{Cl}}_6$ which is/are in the same plane.

The number of species which does not exist among the following

${\mathrm{XeF}}_3^{-}, {\mathrm{SH}}_6, {\mathrm{XeF}}_5 , {\mathrm{NCl}}_5, {\mathrm{PCl}}_5, {\mathrm{PCl}}_3, {\mathrm{XeF}}_3$

Find the number molecules in which bond angle is changed due to back bonding w.r.t. $\mathrm{B}/\mathrm{O}/\mathrm{N}$. 

${\mathrm{H}}_3{\mathrm{BO}}_3, \mathrm{B}(\mathrm{OMe}{)}_3, {\mathrm{BF}}_3, \mathrm{N}{\left({\mathrm{SiH}}_3\right)}_3, \mathrm{O}{\left({\mathrm{SiH}}_3\right)}_2$

Find the number of molecules having pyramidal structure.

${\mathrm{XeO}}_3, {\mathrm{H}}_3{\mathrm{O}}^{+}, {\mathrm{NH}}_3, {\mathrm{PH}}_3, {\mathrm{XeO}}_4, {\mathrm{XeO}}_6^{4-}$

Find the number of compounds which are more covalent in nature compared to ${\mathrm{AlCl}}_3$ from the following.

${\mathrm{AlBr}}_3, {\mathrm{AlI}}_3, {\mathrm{BeCl}}_2, {\mathrm{BeBr}}_2, {\mathrm{AlF}}_3, {\mathrm{BeI}}_2 \left[\mathrm{Given}: {\mathrm{r}}_{{\mathrm{Be}}^{2+}}=0.31 \stackrel{°}{\mathrm{A}}, {\mathrm{r}}_{{\mathrm{Al}}^{3+}}=0.5 \stackrel{°}{\mathrm{A}}\right]$