\(\begin{array}{l}\mathrm{ONCl}=3.2 \mathrm{e}^{-} \\\mathrm{ONO}^{-}=24 \mathrm{e}^{-}\end{array}\)
Thus, ONCl and ONO- are not isoelectronic.
(b) \(\mathrm{O}_{3}\) has bent shape structure. Central atom O is \(s p^{2}\) hybridised with 1 lone pair of electrons.
(c) Ozone is violet-black in solid state.
(d) \(O_{3}\) has no unpaired electrons, thus it is diamagnetic.