---
title: "Manganese (Mn) — element 25"
description: "Manganese is element 25, symbol Mn, atomic weight 54.938. Configuration, properties, uses and neighbours."
url: https://atoneplace.net/element/manganese/
site: "At One Place"
---

# Manganese (Mn)

**Manganese — element 25: Mn**

54.938 u · Transition metal · period 4, group 7

Manganese is the fourth most-used metal by tonnage after iron, aluminium and copper, and almost all of it disappears invisibly into steel — steelmaking simply does not work without it. Hadfield steel, about 12% manganese, has the unusual property of getting harder the more it is battered, which is why it lines rock crushers and railway crossings. Manganese sits at the heart of the oxygen-evolving complex in photosynthesis: a cluster of four manganese atoms in every plant is what splits water and releases the oxygen in the air.

## Properties

- **Atomic number:** 25
- **Symbol:** Mn
- **Standard atomic weight:** 54.938 u
- **Category:** Transition metal
- **Group:** 7
- **Period:** 4
- **Block:** d-block
- **Electron configuration:** [Ar] 4s² 3d⁵
- **Electrons per shell:** 2, 8, 13, 2
- **Melting point:** 1,519 K — 1245.8 °C — 2274.5 °F
- **Boiling point:** 2,334 K — 2060.8 °C — 3741.5 °F
- **Density:** 7.3 g/cm³
- **Electronegativity:** 1.55 (Pauling)
- **Oxidation states:** +7, +4, +3, +2
- **Discovered:** 1774 by Johan Gottlieb Gahn

## Electron configuration

- **Full:** 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵
- **Noble gas shorthand:** [Ar] 4s² 3d⁵
- **Shells:** K: 2 · L: 8 · M: 13 · N: 2

## What it is used for

- Steelmaking — it removes sulfur and oxygen, and nearly all steel contains some
- Manganese dioxide as the cathode in alkaline and zinc-carbon batteries
- Hadfield steel for rock crushers, railway points and excavator teeth
- Potassium permanganate as a disinfectant and water treatment oxidant
- Decolourising glass, which is why it was once called glassmakers' soap

## Hazards

- Chronic inhalation of manganese fume causes manganism, a permanent Parkinson-like condition
- Welders and miners are the usual exposure groups

## Neighbours in the table

| Z | Element | Symbol | Mass |
| --- | --- | --- | --- |
| 23 | Vanadium | V | 50.942 |
| 24 | Chromium | Cr | 51.996 |
| 25 | Manganese ← | Mn | 54.938 |
| 26 | Iron | Fe | 55.845 |
| 27 | Cobalt | Co | 58.933 |

## Group 7

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Manganese sits in group 7 with technetium, rhenium, bohrium.

## Common questions

### What is the atomic number of manganese?

25. That is the number of protons in its nucleus, which is what defines the element.

### What is the symbol for manganese?

Mn.

### What is the electron configuration of manganese?

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵, or [Ar] 4s² 3d⁵ in noble-gas shorthand.

### What is the melting point of manganese?

1,519 K — 1245.8 °C — 2274.5 °F

## Related pages

- [Vanadium (V)](https://atoneplace.net/element/vanadium/)
- [Chromium (Cr)](https://atoneplace.net/element/chromium/)
- [Iron (Fe)](https://atoneplace.net/element/iron/)
- [Cobalt (Co)](https://atoneplace.net/element/cobalt/)
- [Technetium (Tc)](https://atoneplace.net/element/technetium/)
- [Rhenium (Re)](https://atoneplace.net/element/rhenium/)
- [Bohrium (Bh)](https://atoneplace.net/element/bohrium/)

## Sources

- Official vendor product documentation — At One Place (/about/)