AIIMS 2014 Chemistry Atomic Structure MCQ Question

The stability of the ferric ion (Fe³⁺) is primarily attributed to the presence of half-filled d-orbitals. In transition metals, half-filled d-orbitals provide enhanced stability due to symmetrical electron distribution and reduced electron-electron repulsion, which leads to a lower energy state. This stability is particularly significant in the case of Fe³⁺, where the electron configuration results in a half-filled d-subshell (d⁵) when considering the overall stability of its oxidation state.