What is the most stable oxidation state of manganese?

Mn²⁺ (+2) is the most thermodynamically stable aqueous state. Its [Ar] 3d⁵ half-filled d-shell confers extra stability via exchange energy. Mn²⁺ salts are pale pink and stable in water under normal conditions.

Why is permanganate (MnO₄⁻) such a strong oxidant?

In MnO₄⁻, manganese is in the +7 state — the highest attainable. It has an empty or near-empty d-shell ([Ar] 3d⁰) and a strong drive to gain electrons and return to more stable lower states (+2 in acid, +4 in neutral/alkaline), releasing a large amount of free energy per mole.

What color is each manganese oxidation state in solution?

Mn²⁺ is pale pink; Mn³⁺ is red-violet; MnO₄²⁻ (manganate, +6) is deep green; MnO₄⁻ (permanganate, +7) is deep purple/violet. MnO₂ (+4) is a black solid, not appreciably soluble.

What is the electron configuration of manganese?

Ground state Mn is [Ar] 3d⁵ 4s². When forming Mn²⁺, both 4s electrons are lost first, leaving [Ar] 3d⁵. Higher states progressively remove d-electrons: Mn³⁺ is [Ar] 3d⁴, Mn⁴⁺ is [Ar] 3d³, and so on up to Mn⁷⁺ ([Ar] 3d⁰).

Does manganese reach +8 or higher?

No. Mn⁸⁺ is not accessible under ordinary conditions. After the seven valence electrons (3d⁵ 4s²) are removed at +7, breaking into the stable argon core would require extreme energy unavailable in normal chemistry.

What is MnO₂ used for?

Manganese dioxide (MnO₂, Mn in the +4 state) is widely used as a depolarizer in dry-cell batteries (Leclanché cells), as an oxidant in organic synthesis, as a pigment (manganese black), and as a precursor to other manganese compounds.

Manganese Oxidation States

Name: Manganese Oxidation States
Availability: InStock
Author: Nham Vu

Reference for all common and rare oxidation states of manganese (Mn, Z=25), with electron configurations, solution colors, and example compounds for each state.

Atomic # 25 Mn Manganese

Atomic Mass

54.938 u

Group

7 (VIIB)

Period

Block

d-block

Electronegativity

1.55 (Pauling)

Oxidation States

0, +1, +2, +3, +4, +5, +6, +7

Manganese has the widest range of stable oxidation states of any element, spanning 0 to +7. This breadth arises from the availability of all seven outer electrons (3d⁵ 4s²) for bonding, combined with accessible d-orbital energy levels. The +2 state is the most stable in water due to the half-filled d⁵ configuration.

State	Config (after ionization)	Color (solution/solid)	Stability	Example
0	[Ar] 3d⁵ 4s²	Silver-grey metal	Stable	Elemental — Mn metal
+1	[Ar] 3d⁶	Not observed aq.	Rare	Rare — Mn(CO)₅Br (carbonyl)
+2	[Ar] 3d⁵	Pale pink (aq.)	Most stable	Most stable aq. — MnSO₄, MnCl₂
+3	[Ar] 3d⁴	Red-violet (aq.)	Stable	Common — Mn₂O₃, MnF₃
+4	[Ar] 3d³	Black (solid)	Stable	Common solid — MnO₂
+5	[Ar] 3d²	Blue (hypomanganate)	Rare	Rare — MnO₄³⁻
+6	[Ar] 3d¹	Deep green (aq.)	Stable	Alkaline only — K₂MnO₄ (manganate)
+7	[Ar] 3d⁰	Deep purple (aq.)	Stable	Strong oxidant — KMnO₄ (permanganate)

Why +2 is the most stable
Mn²⁺ has a half-filled 3d⁵ configuration, which maximizes exchange energy (all five d-electrons have parallel spins under Hund's rule). This extra stability makes Mn²⁺ reluctant to oxidize further without a strong oxidant, and explains why Mn³⁺ tends to disproportionate to Mn²⁺ and MnO₂ in water.

Manganese forms compounds across every oxidation state from 0 to +7. The most commercially important are MnO₂ (+4, batteries), KMnO₄ (+7, oxidant/disinfectant), and MnSO₄ (+2, fertilizer/pigment). Color and reactivity shift dramatically with state.

Compound	Formula	Mn State	Notes
Manganese metal	Mn	0	Hard, brittle silvery metal. Used in steel alloys to improve hardness and resistance.
Manganese(II) chloride	MnCl₂	+2	Pale pink salt. Soluble in water. Used in dry-cell battery electrolytes and catalysis.
Manganese(II) sulfate	MnSO₄	+2	Pink solid. Major commercial Mn compound; used in fertilizers, feed supplements, and glazes.
Manganese(II) oxide	MnO	+2	Grey-green solid. Used as a colorant in ceramics and glass.
Manganese(III) oxide	Mn₂O₃	+3	Black solid. Found naturally as bixbyite. Intermediate in Mn redox chemistry.
Manganese(III) fluoride	MnF₃	+3	Red-violet solid. Strong fluorinating agent.
Manganese(IV) dioxide	MnO₂	+4	Black solid. Battery depolarizer (Leclanché cells), oxidant in synthesis, pigment.
Potassium manganate	K₂MnO₄	+6	Deep green solid. Intermediate in permanganate production; only stable in strong alkali.
Potassium permanganate	KMnO₄	+7	Deep purple crystals. Powerful oxidant; used in water treatment, organic synthesis, and as a disinfectant.
Sodium permanganate	NaMnO₄	+7	Purple solid, more soluble than KMnO₄. Used in water treatment and as an oxidant in synthesis.
Manganese heptoxide	Mn₂O₇	+7	Unstable dark oily liquid. The anhydride of permanganic acid; highly explosive.
Permanganate ion (acid)	MnO₄⁻	+7	Reduced to Mn²⁺ in acidic solution (gains 5e⁻). The most common permanganate half-reaction.
Permanganate ion (neutral)	MnO₄⁻	+7	Reduced to MnO₂ in neutral/weakly alkaline solution (gains 3e⁻).
Manganate ion	MnO₄²⁻	+6	Deep green; disproportionates in acid to permanganate + MnO₂.

Ground State Configuration

Core (He)

Core

Core (completes [Ne])

Core

Core (completes [Ar])

Valence — half-filled (gives +2 stability)

Valence — lost first on ionization

Notation

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²

Noble gas: [Ar] 3d⁵ 4s²

Mn²⁺: [Ar] 3d⁵ — half-filled d

Ionization Steps (4s then 3d)

[Ar] 3d⁵ 4s²

Neutral — 7 valence electrons

Mn⁺

[Ar] 3d⁵ 4s¹

Remove one 4s electron

Mn²⁺

[Ar] 3d⁵

Remove last 4s — stable half-filled d shell

Mn³⁺

[Ar] 3d⁴

Remove first 3d — significant oxidant needed

Mn⁴⁺

[Ar] 3d³

e.g. in MnO₂

Mn⁵⁺

[Ar] 3d²

Rare; hypomanganate

Mn⁶⁺

[Ar] 3d¹

Manganate (green, alkaline only)

Mn⁷⁺

[Ar] 3d⁰

Permanganate — all d-electrons removed

Half-filled d⁵ and exchange energy
Mn²⁺ ([Ar] 3d⁵) has all five d-electrons with parallel spins. This maximizes electron exchange interactions, releasing extra stabilization energy. It is the main reason Mn²⁺ is far more stable than its neighbors Cr²⁺ or Fe²⁺ in aqueous solution.

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Summary

Reference for all common and rare oxidation states of manganese (Mn, Z=25), with electron configurations, solution colors, and example compounds for each state.

How it works

Click a tab — Oxidation States, Compounds, Electron Config, or Physical Props — to explore each section.
The Oxidation States tab shows each state with its electron configuration, color indicator, and stability rating.
The Compounds tab lists named compounds for each oxidation state with formulas and context.
The Electron Config tab diagrams the d-orbital filling from Mn(0) to Mn(VII).
The Physical Props tab provides atomic and material data for quick lookup.
Click any formula cell to copy it to the clipboard.

Use cases

Students studying transition metal chemistry and oxidation state rules.
Chemistry teachers preparing lessons on variable oxidation states and d-block trends.
Lab chemists identifying Mn species by color in solution (permanganate, manganate, Mn²⁺).
Researchers working with MnO₂ batteries, permanganate oxidations, or biomimetic catalysis.
Anyone preparing for exams covering d-block or first-row transition metal chemistry.
Environmental scientists studying manganese redox cycling in water and soil.

Frequently Asked Questions

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