How does the electronic configuration of Fe²⁺ compared to Mn²⁺ explain the lower ionization enthalpy of Fe²⁺, and what conclusion can be drawn about the third ionization enthalpy of Fe relative to Mn?

The electronic configuration of Fe²⁺, with a d⁶ configuration, differs from Mn²⁺, which has a 3d⁵ configuration. In the absence of exchange energy loss in the d⁶ configuration of Fe²⁺, its ionization enthalpy is lower than that of Mn²⁺. This lower ionization enthalpy of Fe²⁺ compared to Mn²⁺ suggests that Fe²⁺ is more stable due to the absence of exchange energy loss. Consequently, it can be concluded that the third ionization enthalpy of Fe would also be lower than that of Mn, emphasizing the impact of electronic configurations on ionization enthalpies.