Manganese (Mn)
Element 25 · Transition metal · atomic mass 54.938 u · group 7, period 4
Electron shells: 2, 8, 13, 2
Manganese is essential to modern steelmaking — it removes sulfur and oxygen and adds hardness. Biologically it sits at the heart of the enzyme that splits water during photosynthesis.
Almost 90% of all manganese mined goes straight into steel.
- Atomic number
- 25
- Atomic mass
- 54.938 u
- Electron configuration
- [Ar] 4s² 3d⁵
- Group · period · block
- 7 · 4 · d
- Oxidation states
- +2, +3, +4, +7
- Electronegativity
- 1.55 (Pauling)
- Melting point
- 1,246 °C
- Boiling point
- 2,061 °C
- Density
- 7.3 g/cm³
- State at 20 °C
- Solid
- Appearance
- Hard, brittle grey metal
- Discovered
- Johan Gottlieb Gahn, 1774
25 protons, and 25 electrons when neutral
IUPAC standard atomic weight
Manganese group
What Manganese is used for
- Steel alloying and desulfurisation
- Alkaline and lithium-ion battery cathodes
- Aluminium can alloys
- Glass decolourising
Atomic structure of Manganese
A neutral manganese atom has 25 protons and 25 electrons. Its most common isotope carries about 30 neutrons, which is where the mass number 55 comes from. Change the neutron count and you have a different isotope of manganese; change the proton count and you have a different element entirely.
Those electrons fill shells from the inside out: 2, 8, 13, 2. In orbital notation that is [Ar] 4s² 3d⁵. As a d-block element its valence count is variable, which is why it can form compounds in several oxidation states.
3D electron orbitals
See where Manganese's electrons actually are — a cloud of 26,000 points sampled from the probability density |ψ|², not a cartoon of a lobe.
Where Manganese sits in the periodic table
The d-block. Multiple stable oxidation states give them coloured compounds, catalytic ability and the strength that makes them the working metals of industry.
- Directly below: Technetium — same group, one shell larger.
- One proton lighter: Chromium.
- One proton heavier: Iron.
Discovery and naming
Manganese was discovered by Johan Gottlieb Gahn in 1774. Its name comes from Latin magnes, "magnet", via magnesia nigra, which is also why its symbol (Mn) does not match its English name.
Keep exploring
Atomic weight from IUPAC/CIAAW; physical properties from PubChem (US National Library of Medicine). Values that have never been measured are shown as “not measured” rather than estimated.
Related Calculators
Frequently Asked Questions
What is the atomic mass of Manganese?
The standard atomic weight of Manganese is 54.938 u, as published by IUPAC's Commission on Isotopic Abundances and Atomic Weights.
How many protons, neutrons and electrons does Manganese have?
Manganese has 25 protons, because the atomic number is the proton count and that is what makes an atom Manganese at all. A neutral Manganese atom has the same number of electrons, 25. The neutron count varies by isotope; the most common one has about 30, since 55 − 25 = 30.
What is the electron configuration of Manganese?
The electron configuration of Manganese is [Ar] 4s² 3d⁵. Its electrons are arranged 2, 8, 13, 2 across 4 shells.
Is Manganese a metal?
Yes. Manganese is classified as a transition metal, on the metallic side of the table.
What group and period is Manganese in?
Manganese is in group 7 (the manganese group), period 4, in the d-block. The group is its column and the period is its row.
What is the charge of Manganese?
Manganese most commonly forms a 2+ ion. Like most transition metals it has several accessible oxidation states, so the charge depends on the compound. Across all its compounds it shows oxidation states of +2, +3, +4, +7.
What is the melting point of Manganese?
Manganese melts at 1,246 °C and boils at 2,061 °C. That puts it in the solids at everyday temperatures.
What is Manganese used for?
Steel alloying and desulfurisation, Alkaline and lithium-ion battery cathodes, Aluminium can alloys, Glass decolourising. Manganese is essential to modern steelmaking — it removes sulfur and oxygen and adds hardness.
Who discovered Manganese, and where does its name come from?
Manganese (Mn) was discovered by Johan Gottlieb Gahn in 1774. The name comes from Latin magnes, "magnet", via magnesia nigra.