alleryPauli's exclusion principle states that:
AAll electrons have the same spin in an atom
BNo two electrons share all four quantum numbers
CTwo electrons cannot occupy the same orbital
DEnergy of all electrons is fully quantised
Answer & Solution
Correct answer: B. No two electrons share all four quantum numbers
1. Pauli (1925): no two electrons in the same atom can have all four quantum numbers identical.
2. Hence each orbital (defined by n, ℓ, m_ℓ) holds at most TWO electrons, differing in m_s = +½ and −½.
3. Statement (C) is too narrow (rule out scope of triple/quadruple occupancy).
_Source: syllabus Chem Ch 2 §2.6 Pauli Exclusion Principle_
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