$A$ pair of molecules with see-saw shape and linear shape,respectively,is

In which of the following sets,all the given species are isostructural?

Find the maximum number of atoms present in the same plane in a $PCl_5$ molecule.

Which of the following molecules is non-linear?

Select from each set the molecule or ion having the smallest bond angle:
$(i)$ $NH_3, PH_3$ or $AsH_3$
$(ii)$ $O_3^+, O_3$
$(iii)$ $NO_2^-$ or $O_3$
$(iv)$ $X-S-X$ angle in $SOCl_2$ and $SOF_2$

What are the number of bond pairs and the number of lone pair electrons in $OF_2$,respectively?