Which principle states that no two electrons in an atom can have the same set of quantum numbers?

The principle that states no two electrons in an atom can have the same set of quantum numbers is the Pauli exclusion principle. This principle, formulated by Wolfgang Pauli in 1925, is fundamental to understanding the arrangement of electrons in atoms and the behavior of atoms in general.

Quantum numbers are a set of numerical values that describe the unique state of an electron within an atom, including its energy level, shape of the orbital, orientation in space, and the spin of the electron. According to the Pauli exclusion principle, each electron in a multi-electron atom must differ in at least one of these quantum numbers from every other electron. This underpins the electron configuration of atoms, directly influencing chemical properties and bonding behavior.

In contrast, the Heisenberg uncertainty principle addresses the limitations in simultaneously knowing the exact position and momentum of a particle, rather than the arrangement of electrons. Hund's rule explains how electrons fill orbitals in a way that maximizes the total spin before pairing up, while the Bohr model relates to quantized orbits of electrons in a hydrogen atom but does not encompass the broader implications of quantum numbers as described by the Pauli exclusion principle.