Deep dive

Quantum Numbers And Orbitals

Quantum numbers label allowed electron states in atoms: principal, orbital angular momentum, magnetic and spin quantum numbers.

How the ideas connect

A good science page should make the connection visible, not just list definitions.

Quantum numbers

Quantum numbers label allowed electron states in atoms: principal, orbital angular momentum, magnetic and spin quantum numbers.

They are not arbitrary addresses; together they encode energy-scale, orbital shape/orientation information and spin state within the quantum model.

→ Quantum numbers

Atomic orbitals

An atomic orbital is a quantum-mechanical description associated with an electron state in an atom, not a tiny classical path.

The familiar s, p, d and f labels organize electronic structure and help make sense of the architecture of the periodic table.

→ Atomic orbitals

Pauli exclusion principle

The Pauli exclusion principle states that no two identical fermions can occupy the same quantum state. In an atom, no two electrons can share all four quantum numbers.

This rule is fundamental to electron-shell structure and therefore to the architecture of the periodic table.

→ Pauli exclusion principle

Hund's rule

Hund’s rule describes the lowest-energy filling pattern within a set of degenerate orbitals: electrons occupy different orbitals with parallel spins before pairing, in the usual atomic model.

It helps explain ground-state electron configurations and magnetic behaviour, but it belongs to a broader quantum-mechanical energy picture.

→ Hund's rule

What to notice

A good science page should make the connection visible, not just list definitions.

Sources

IUPAC Gold Book · NIST · BIPM