Manganese
Atomic Data
| Atomic Number | 25 |
| Symbol | Mn |
| Atomic Weight | 54.938 u |
| Density (STP) | 7.21 g/cm³ |
| Melting Point | 1245.85 °C (1519 K) |
| Boiling Point | 2060.85 °C (2334 K) |
| Electronegativity | 1.55 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d5 4s2 |
| Oxidation States | +2, +3, +4, +6, +7 |
| Phase at STP | Solid |
| Category | Transition Metal |
| Period / Group | 4 / 7 |
| CAS Number | 7439-96-5 |
Electron Configuration
[Ar] 3d5 4s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 5 | 23 |
| N | 4 | 4s | 2 | 25 |
| Total | 25 | 25 | ||
Isotopes of Manganese
Manganese is monoisotopic: ⁵⁵Mn is its only naturally occurring stable isotope, accounting for 100% of all natural Manganese.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Manganese-55 | ⁵⁵Mn | 25 | 30 | 100 | Stable |
Abundance & Occurrence
Manganese is present in Earth's crust at approximately 950 ppm by mass and at approximately 8 ppm by mass throughout the universe.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Read more about the discovery of the periodic table of elements →
Safety & Handling
- Manganese dust inhalation: manganism: Chronic inhalation of manganese dust or fumes (from welding on manganese-containing steel) causes manganism, a progressive neurological disorder resembling Parkinson's disease; neurological damage may be irreversible.
- Welding fumes: Welding on steel containing manganese generates Mn-containing fumes; these are classified as Group 1 human carcinogens (IARC) for lung cancer and as neurotoxins: adequate local exhaust ventilation is mandatory.
- Potassium permanganate (KMnO4): A strong oxidiser that reacts vigorously with organic materials and reducing agents; contact with glycerol or other organics can cause spontaneous ignition; solutions are corrosive to skin.
- Dust fire hazard: Manganese powder is combustible; use Class D extinguishing agents for metal fires.
Manganese in the Real World
Real-World Uses
- Steel production: Manganese is added to virtually all steel (0.25–2%) as a deoxidiser, desulfuriser, and alloying agent that increases hardenability, tensile strength, and wear resistance; Hadfield steel (10–15% Mn) is exceptionally tough and is used in rock-crushing equipment.
- Dry cell batteries: Manganese dioxide (MnO₂) is the cathode material in alkaline and zinc-carbon batteries, accepting electrons as zinc is oxidised at the anode to deliver electrical current.
- Aluminium alloys: Small amounts of manganese (Mn in the 3xxx series alloys) improve strength, workability, and corrosion resistance in aluminium alloys used for beverage cans, cooking foil, and heat exchangers.
- Pigments and glass: Manganese compounds have been used as pigments since prehistoric cave paintings; manganese dioxide is added to glass to decolourise it by oxidising green iron(II) to less-coloured iron(III).
- Fertiliser and animal feed: Manganese is an essential trace element for plant enzymes involved in photosynthesis and nitrogen metabolism; manganese sulfate is applied to manganese-deficient soils and included in animal feed supplements.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
What is manganese used for?
Manganese is essential for steel production: virtually all steel contains manganese as a desulfurizer and deoxidizer, and high-manganese steels are extremely hard and wear-resistant. Manganese is also used in dry-cell batteries, as a pigment in bricks and glass, and as a nutritional additive in fertilisers and animal feeds.
Is manganese toxic?
Manganese is an essential trace element for humans, important for enzyme function and bone formation. However, excessive exposure: particularly through inhalation of manganese dust or fumes in mining or welding: can cause manganism, a neurological disorder with symptoms resembling Parkinson's disease. Safe levels are well below those encountered in most daily life.
How was manganese discovered?
Manganese was recognized as a distinct element in 1774 by Swedish chemist Carl Wilhelm Scheele, who showed it was not the same as iron or magnesium. His colleague Johan Gottlieb Gahn isolated the metal for the first time the same year by reducing manganese dioxide with carbon. Its name derives from Magnesia, a region of Greece where manganese ores were mined in antiquity.
What are high-manganese steels?
High-manganese steels (also called Hadfield steels, after their inventor Robert Hadfield) contain 11–14% manganese. Under impact, these steels work-harden at the surface while the bulk remains tough, making them exceptionally wear-resistant. They are used in rock crusher jaws, railway track crossings, and the digging edges of excavator buckets.