Question

Among the following series of transition metal ions, the one where all metal ions have 3d2electronic configuration is :-

Answer 1

ElementProton numberElectron configurationDiagramSc21[Ar] 3d1 4s2Ti22[Ar] 3d2 4s2V23[Ar] 3d3 4s2Cr24[Ar] 3d5 4s1Mn25[Ar] 3d5 4s2Fe26[Ar] 3d6 4s2Co27[Ar] 3d7 4s2Ni28[Ar] 3d8 4s2Cu29[Ar] 3d10 4s1Zn30[Ar] 3d10 4s2

Transition metal ionsEdit

The electronic configurations of transition metal ions can seem counter-intuitive. For neutral transition metal atoms, the 4s subshell fills first, followed by the 3d subshell, which we assume is because 3d is slightly higher in energy than 4s.

However, in transition metal ions, the 4s empties first, which implies that it is higher in energy than the 3d. So which is higher in energy, 3d or 4s? The answer is they are very close in energy, and changing from a neutral atom to an ion causes the 3d to decrease in energy relative to the 4s, meaning that in ions, the 4s empties first, whereas in neutral atoms, the 4s fills first.

SpeciesProton numberElectron configurationDiagramTi22[Ar] 3d2 4s2Ti+22[Ar] 3d2 4s1Ti2+22[Ar] 3d2Ti3+22[Ar] 3d1Ti4+22[Ar]