`+2` oxidation state of manganese and zinc is very stable. Explain.

Explanation

With increase in atomic number of the first transition series, the stability of + 2 oxidation state decreases since the first and second ionisation enthalpies collectively increase across the series. However, `Mn^(2+)(3d^(5))` and `Zn^(2+)(3d^(10))` have half - filled and completely filled d - orbitals, respectively. Hence, in the + 2 oxidation state these metal ions are very stable.