Electron Configuration

Quantum numbers, orbitals, electron configurations, orbital diagrams, and valence electrons.

Intended level

Intermediate — requires Atomic Structure.

Prerequisites

• atomic-structure

Ordered lessons

1. orbitals quantum numbers
2. electron configuration orbital diagrams
3. valence electrons
4. effective nuclear charge shielding

Related formulas and calculators

• $electron-configuration-notation$ — see Formula: electron-configuration-notation
• electron-config

Only links to real, published tools are shown. Placeholders are not linked.

Common misconceptions

• Electrons fill orbitals randomly.
• Valence electrons are all electrons in an atom.
• Quantum numbers are arbitrary labels.

Related resources

• Constants — sourced physical constants with version stamps.
• Laboratory Safety — PPE, hazards, RAMP.
• Glossary — definitions for key terms in this topic.
• Sources and Data — how sources are versioned and cited.

Curriculum mappings

This topic maps to external frameworks stored in src/content/curriculum/. Never implies official affiliation.

• AP Chemistry 1.1 / IB Chemistry 2.1 (see /curriculum/ap-chem-1-1 and file src/content/curriculum/ap-chem-1-1.md).
• Framework version and source URL recorded per mapping; review date 2026-08-21.

Review and source metadata

• Author: Chemistry Fundamentals Editorial Team (chem-team)
• Reviewer: Dr. Example Reviewer (chemistry reviewer — transparent placeholder, see /editorial-policy)
• Last reviewed: 2026-08-21
• Review due: 2027-08-21
• Sources: NIST Reference Placeholder (nist-2022, 2022-CODATA). Placeholder reference — replace with actual sourced reference per lesson.

Printable summary

Summary card (PDF) — coming soon — print styles preserve equations and tables.

Correction? See Corrections Policy and Contact.