Find the number of planar molecules.

(a) ${\mathrm{BF}}_3$               (b) ${\mathrm{BCI}}_3$

(C) ${{\mathrm{CO}}_3}^{2-}$        (d) ${\mathrm{SO}}_3$

(e) ${\mathrm{NH}}_3$             (f) ${\mathrm{NCl}}_3$

(g) ${\mathrm{PCl}}_3$            (h) ${\mathrm{PF}}_3$ 

When all of a molecule's atoms are in the same plane, it is said to be "planar."
All of the atoms in ${\mathrm{BF}}_3$,${\mathrm{BCI}}_3$,${{\mathrm{CO}}_3}^{2-}$,${\mathrm{SO}}_3$   are located in the same plane. They are planer as a result.

a, b, c, d