Aufbau (Building-Up) Principle
| Formula / Notation | 1s, 2s, 2p, 3s, 3p, 4s, 3d... (filling order) |
|---|---|
| Also Known As | Building-up principle; Aufbauprinzip; orbital filling rule; electron configuration rule; n+l rule |
What is Aufbau (Building-Up) Principle?
The Aufbau principle states that electrons fill atomic orbitals in order of increasing energy, from the lowest available orbital upward. The filling sequence follows the n + l rule: orbitals with lower (n + l) values are filled first. This principle, combined with the Pauli exclusion principle and Hund's rule, describes the ground-state electron configuration of atoms.
Formula & Notation
Other Names / Synonyms: Building-up principle; Aufbauprinzip; orbital filling rule; electron configuration rule; n+l rule
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
The Aufbau principle states that electrons fill atomic orbitals in order of increasing energy, from the lowest available orbital upward. The filling sequence follows the n + l rule: orbitals with lower (n + l) values are filled first. This principle, combined with the Pauli exclusion principle and Hund's rule, describes the ground-state electron configuration of atoms.
Predicting electron configurations; understanding chemical reactivity; basis of periodic table structure; explaining spectroscopic data; foundation of quantum chemistry
No hazard — a theoretical principle.
The formula or notation for Aufbau (Building-Up) Principle is: 1s, 2s, 2p, 3s, 3p, 4s, 3d... (filling order)