Full configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²
In the short form, [Ar] stands for the 18 electrons of argon, the noble gas before manganese. Only the electrons after it are written out.
Orbital diagram
Outer subshells only. Each box is an orbital; electrons fill singly first (Hund's rule), then pair up with opposite spins.
What the configuration tells you
Manganese has five unpaired 3d electrons, and Mn²⁺ (3d⁵) is especially stable. It shows the widest range of oxidation states in the 3d series, up to +7 in KMnO₄.
Configuration of manganese ions
| Ion | Configuration | Unpaired | Moment (BM) |
|---|---|---|---|
| Mn²⁺ | [Ar] 3d⁵ | 5 | 5.92 |
| Mn⁴⁺ | [Ar] 3d³ | 3 | 3.87 |
| Mn⁷⁺ | [Ar] | 0 | 0.00 |
Moment is the spin-only magnetic moment μ = √(n(n + 2)) Bohr magnetons, where n is the number of unpaired electrons. Positive ions lose electrons from the outermost shell first, so transition metals lose their 4s or 5s electrons before d.
Nearby elements
| Z | Element | Configuration |
|---|---|---|
| 22 | Titanium | [Ar] 3d² 4s² |
| 23 | Vanadium | [Ar] 3d³ 4s² |
| 24 | Chromium | [Ar] 3d⁵ 4s¹ |
| 26 | Iron | [Ar] 3d⁶ 4s² |
| 27 | Cobalt | [Ar] 3d⁷ 4s² |
| 28 | Nickel | [Ar] 3d⁸ 4s² |
Questions students ask
What is the electronic configuration of manganese?
[Ar] 3d⁵ 4s², or in full, 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s². Manganese has atomic number 25.
How many electrons are in each shell of manganese?
2, 8, 13, 2 (K, L, M, N… shells in order).
How many unpaired electrons does manganese have?
5 in the ground state, so manganese atoms are paramagnetic.
What is the electronic configuration of Mn²⁺?
[Ar] 3d⁵, with 5 unpaired electrons.