Chemistry - Atomic Structure Question with Solution | TestHub

Consider the following ions

$1.$$\mathrm{N}{\mathrm{i}}^{2+}$

$2.$$\mathrm{C}{\mathrm{o}}^{2+}$

$3.$$\mathrm{C}{\mathrm{r}}^{2+}$

$4.$$\mathrm{F}{\mathrm{e}}^{3+}$

Atomic number: Cr = 24, Fe = 26, Co = 27, Ni = 28.

The correct sequence of increasing order of the number of unpaired electrons in these ions is