Aluminium Electron Configuration

Interactive reference for aluminium's electron configuration (1s² 2s² 2p⁶ 3s² 3p¹), orbital diagram, quantum numbers, and key atomic properties.

Use the Aluminium Electron Configuration

Z = 13 Al Aluminium

Aluminium — Electron Configuration

Atomic number 13 · Post-transition metal · Period 3, Group 13 · p-block

1s² 2s² 2p⁶ 3s² 3p¹ [Ne] 3s² 3p¹ 13 electrons 3 valence e⁻

Subshell Breakdown

Subshell Type Electrons Max Capacity Notation
1s s orbital, shell n=1 2 2 1s²
2s s orbital, shell n=2 2 2 2s²
2p p orbitals, shell n=2 6 6 2p⁶
3s s orbital, shell n=3 2 2 3s²
3p p orbitals, shell n=3 1 6 3p¹
Total 13

Full Configuration

1s² 2s² 2p⁶ 3s² 3p¹

All subshells written explicitly.

Noble-Gas Shorthand

[Ne] 3s² 3p¹

[Ne] = 1s² 2s² 2p⁶ (the filled neon core).

Shell Fill Summary

Shell 1 (n=1) — 1s² 2 / 2 electrons (100%)
Shell 2 (n=2) — 2s² 2p⁶ 8 / 8 electrons (100%)
Shell 3 (n=3) — 3s² 3p¹ 3 / 18 electrons (17%)

Shell 3 can hold up to 18 electrons (3s + 3p + 3d). Aluminium uses only 3 of those 18 slots.

Summary

Aluminium (Al) has atomic number 13 and the ground-state electron configuration 1s² 2s² 2p⁶ 3s² 3p¹. This tool displays its full orbital diagram, subshell-by-subshell breakdown, and noble-gas shorthand ([Ne] 3s² 3p¹), along with a quantum-number table for all 13 electrons and key physical and chemical properties. It is a quick, reliable reference for students, teachers, and anyone studying periodic-table chemistry.

How it works

  1. The Aufbau principle fills orbitals from lowest to highest energy.
  2. Aluminium's 13 electrons occupy five subshells: 1s, 2s, 2p, 3s, and 3p.
  3. The 2p subshell holds 6 electrons across three orbitals (2pₓ, 2p_y, 2p_z), each pair-filled.
  4. The 3p subshell holds only 1 electron — the lone valence p electron that makes Al a metal with +3 oxidation state.
  5. Noble-gas notation replaces the inner filled shells with the nearest noble gas in brackets: [Ne] 3s² 3p¹.
  6. The interactive tabs let you explore the configuration, orbital diagram, and element data separately.

Use cases

  • Quick reference for chemistry homework or exam review.
  • Visualize orbital filling order through the s and p blocks.
  • Understand why aluminium forms a +3 ion by losing its three outermost electrons.
  • Compare aluminium to other Group 13 (IIIA) post-transition metals.
  • Learn how the 3p¹ configuration explains aluminium's reactivity and bonding.
  • Teaching aid for introductory atomic structure and periodic trends lessons.
  • Verify quantum numbers for each of aluminium's 13 electrons.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu