What does Hund's Rule state regarding electron configuration in degenerate orbitals?

Hund's Rule is a fundamental principle in quantum chemistry that addresses how electrons are distributed in degenerate orbitals, which are orbitals that have the same energy level. According to this rule, when electrons are assigned to these orbitals, one electron is placed in each degenerate orbital before any orbital gets a second electron. This results in maximized spin multiplicity, which means that having unpaired electrons in the orbitals minimizes electron-electron repulsions and stabilizes the atom.

This principle is particularly important in determining the ground state electron configuration of atoms, especially for those in the p, d, and f blocks of the periodic table. By following Hund's Rule, you ensure that the electron configuration reflects a more stable arrangement, as unpaired electrons will have parallel spins, leading to lower energy states due to reduced repulsion among electrons.

This understanding supports the correct answer, which asserts that one should fill each degenerate orbital singly before any pairing occurs. Other options, while related to electron configurations, do not accurately describe Hund's Rule and its implications for electron distribution in orbitals.