Chemistry - Complete d-block Question with Solution | TestHub

Among the following series of transition metal ions, how many metals ions have${\text{d}}^{\text{2}}$electronic configuration

$\mathrm{F}{\mathrm{e}}^{4+},{\mathrm{V}}^{3+},\mathrm{S}{\mathrm{n}}^{2+},\mathrm{A}{\mathrm{u}}^{3+}\mathrm{T}{\mathrm{i}}^{2+},\mathrm{A}{\mathrm{s}}^{3+},\mathrm{C}{\mathrm{r}}^{3+},\mathrm{M}{\mathrm{n}}^{5+}\mathrm{C}{\mathrm{o}}^{3+},\mathrm{Z}{\mathrm{r}}^{2+},\mathrm{C}{\mathrm{d}}^{2+},\mathrm{M}{\mathrm{o}}^{4+},\mathrm{L}{\mathrm{a}}^{2+},\mathrm{T}{\mathrm{a}}^{4+},\mathrm{C}{\mathrm{o}}^{6+},\mathrm{N}{\mathrm{i}}^{4+}$