Question

In which of the following pairs the two species are not isostructural ?
(a) $CO_3^{2-}$ and $NO_3^-$
(b) $PCl_4^+$ and SiCl₄
(c) PF₅ and BrF₅
(d) $AlF_6^{3-}$ and SF₆

Answer 1

the answer to this questions is

D