Manganese Electron Configuration

Interactive reference for manganese's electron configuration (1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²), orbital box diagram, quantum numbers, and key atomic properties.

Z = 25 Mn Manganese

Manganese — Electron Configuration

Atomic number 25 · Transition metal · Period 4, Group 7 · d-block

1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s² [Ar] 3d⁵ 4s² 25 electrons 7 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 6 6 3p⁶
3d d orbitals, shell n=3 5 10 3d⁵
4s s orbital, shell n=4 2 2 4s²
Total 25

Full Configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²

All subshells written explicitly.

Noble-Gas Shorthand

[Ar] 3d⁵ 4s²

[Ar] = 1s² 2s² 2p⁶ 3s² 3p⁶ (the filled argon core).

Why the Half-Filled 3d⁵ Matters

The 3d subshell in manganese holds exactly 5 electrons — one per orbital, all with parallel spins. This half-filled arrangement maximizes exchange energy, making it particularly stable. It explains manganese's wide range of oxidation states (+2 through +7) and its role in biological processes such as photosynthesis (Mn in Photosystem II).

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 3p⁶ 3d⁵ 13 / 18 electrons (72%)
Shell 4 (n=4) — 4s² 2 / 32 electrons (6%)

Shell 3 can hold up to 18 electrons (3s + 3p + 3d). Manganese uses 13 of them. Shell 4 can hold 32; only 2 are used.

Summary

Interactive reference for manganese's electron configuration (1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²), orbital box diagram, quantum numbers, and key atomic properties.

How it works

  1. The Aufbau principle fills orbitals from lowest to highest energy: 1s → 2s → 2p → 3s → 3p → 4s → 3d.
  2. After the argon core (1s² 2s² 2p⁶ 3s² 3p⁶), the 4s subshell fills first (before 3d) because it is lower in energy for Z=25.
  3. The 3d subshell then receives 5 electrons — exactly one per orbital — giving a half-filled 3d⁵ configuration.
  4. Hund's rule maximizes spin multiplicity: each of the five 3d electrons occupies a separate orbital with parallel (all spin-up) spins.
  5. The half-filled 3d⁵ is unusually stable, explaining manganese's chemistry and its multiple oxidation states.
  6. Noble-gas notation replaces the argon inner core with [Ar], leaving [Ar] 3d⁵ 4s² as the abbreviated form.

Use cases

  • Quick reference for chemistry homework or exam review on transition metals.
  • Understand why the 3d subshell is half-filled in manganese and what that means.
  • Learn how the 3d⁵ 4s² configuration gives manganese 7 valence electrons and multiple oxidation states.
  • Visualize orbital filling across the d-block using the interactive orbital diagram.
  • Compare manganese to neighboring transition metals (chromium, iron) for periodic trend study.
  • Teaching aid for Aufbau principle, Hund's rule, and d-block chemistry lessons.
  • Verify quantum numbers for all 25 electrons of manganese.

Frequently Asked Questions

Last updated: 2026-07-08 · Reviewed by Nham Vu