The comparatively high value for Mn signifies the stability of Mn²⁺(d⁵), while the comparatively low value for Fe highlights the extra stability associated with Fe³⁺(d⁵), showcasing the influence of electron configurations on oxidation state stability.

Cr and Cu show high second ionization enthalpies due to the removal of electrons from d orbitals, resulting in d⁵ and d¹⁰ configurations in M²⁺ ions, influencing their stability.

Fe²⁺ has a d⁶ configuration, while Mn²⁺ has a 3d⁵ configuration. The absence of exchange energy loss in the d⁶ configuration of Fe²⁺ results in lower ionization enthalpy compared to Mn²⁺, indicating that the third ionization enthalpy of Fe is ...

Mn⁺ has a 3d⁵4s¹ configuration, while Cr⁺ has a d⁵ configuration. The absence of loss of exchange energy in the d⁶ configuration of Mn⁺ leads to lower ionization enthalpy compared to Cr⁺, showcasing the influence of exchange energy on stability ...

The variation in ionization enthalpy for dⁿ configuration is influenced by the attraction of electrons towards the nucleus, repulsion between electrons, and exchange energy. Exchange energy, proportional to the number of possible pairs of parallel spins, increases stability by following ...