E

Electron Configuration

e.g., Na: 1s²2s²2p⁶3s¹ or [Ne]3s¹; uses Aufbau, Pauli, Hund's rules
Quick Reference
Formula / Notatione.g., Na: 1s²2s²2p⁶3s¹ or [Ne]3s¹; uses Aufbau, Pauli, Hund's rules
Also Known AsElectronic configuration, orbital filling, ground state electron configuration

What is Electron Configuration?

The distribution of electrons in an atom among its atomic orbitals, following the Aufbau principle, Pauli exclusion principle, and Hund's rule. Written using orbital notation (e.g., 1s²2s²2p⁶), electron configurations determine chemical properties and reactivity.

Formula & Notation

e.g., Na: 1s²2s²2p⁶3s¹ or [Ne]3s¹; uses Aufbau, Pauli, Hund's rules

Other Names / Synonyms: Electronic configuration, orbital filling, ground state electron configuration

Properties & Characteristics

Electron configuration describes the distribution of electrons in the orbitals of an atom or ion, following the Aufbau principle (lowest energy filled first), Pauli exclusion principle (max 2 electrons per orbital, opposite spins), and Hund's rule (maximize unpaired electrons in degenerate orbitals). Orbitals are filled in the order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p... Some elements (Cr, Cu) show anomalous configurations due to extra stability of half-filled and filled d subshells.

Uses & Applications

Electron configurations explain periodic trends (atomic radius, IE, EA), chemical reactivity, magnetic properties, and spectroscopic behaviour. They are fundamental to explaining why elements in the same group have similar chemistry and to the design of materials with specific electronic properties.

Safety Information

No direct safety hazard. Understanding electron configuration helps predict which elements are strong oxidisers (electron-deficient configs) or strong reducing agents (easily lose electrons), guiding safe chemical practice.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Electron Configuration
Formula e.g., Na: 1s²2s²2p⁶3s¹ or [Ne]3s¹; uses Aufbau, Pauli, Hund's rules
Synonyms Electronic configuration, orbital filling, ground state electron configuration

Frequently Asked Questions

The distribution of electrons in an atom among its atomic orbitals, following the Aufbau principle, Pauli exclusion principle, and Hund's rule. Written using orbital notation (e.g., 1s²2s²2p⁶), electron configurations determine chemical properties and reactivity.

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