The extra stability of half-filled subshell is due to
(A) Symmetrical distribution of electrons
(B) Smaller coulombic repulsion energy
(C) The presence of electrons with the same spin in non-degenerate orbitals
(D) Larger exchange energy
(E) Relatively smaller shielding of electrons by one another
Identify the correct statements
Show Hint
The enhanced stability of half-filled and fully filled subshells arises from a combination of factors related to electron arrangement and interactions. Symmetrical distribution minimizes repulsion and can slightly affect shielding, while maximized exchange energy provides a significant stabilizing effect.
This question concerns the enhanced stability of half-filled electron subshells in atoms, a fundamental concept in electronic configurations and atomic structure within chemistry.
Electron Symmetry (Option A): Half-filled subshells exhibit symmetrical electron distribution. This symmetry stabilizes the atom by creating a more uniform electron cloud, thereby minimizing electron-electron repulsion.
Reduced Coulombic Repulsion (Option B): In a half-filled subshell, electrons are distributed evenly among orbitals, maximally reducing repulsion between them. This diminished repulsion leads to lower energy and increased stability.
Increased Exchange Energy (Option D): Exchange energy, a quantum mechanical phenomenon, allows electrons in degenerate orbitals to exchange positions. This exchange process, most frequent in half-filled subshells, lowers the atom's energy, enhancing stability.
Limited Electron Shielding (Option E): A half-filled configuration results in a more even spread of electrons. This even distribution reduces the shielding effect, where inner electrons impede the attraction between the nucleus and outer electrons. Decreased shielding strengthens the nuclear attraction on outer electrons, further stabilizing the atom.
Consequently, the accurate statements are (A), (B), (D), and (E), aligning with the provided correct answer: (A), (B), (D), and (E) exclusively.
