JAMB Chemistry 2024 Paper

Concept:The Pauli Exclusion Principle describes the limitation on identical quantum states for electrons in an atom.Explanation:Each electron is described by four quantum numbers: $n$, $l$, $m_l$, and $m_s$.No two electrons in the same atom can have the same value for all four quantum numbers.Thus, an orbital can hold at most two electrons, and they must have opposite spins: $m_s = +\frac{1}{2}$ and $m_s = -\frac{1}{2}$.The Aufbau principle only explains the order of filling orbitals by increasing energy.Hund's rule explains that electrons occupy degenerate orbitals singly before pairing up.Therefore, the principle stated in the question is the Pauli Exclusion Principle.Answer:Option C: Pauli Exclusion Principle.