WebElements

Periodic Table

manganese

Atomic number: 25
Atomic weight: 54.93804
Symbol: Mn
Group number: 7
Electronic configuration: [Ar].3d5.4s2

Description

The metal is gray-white, resembling iron, but is harder and very brittle. The metal is reactive chemically, and decomposes cold water slowly. Manganese is widely distributed throughout the animal kingdom. It is an important trace element and may be essential for utilisation of vitamin B. Manganese is present in quantity the floor of oceans. It is an important component of steel.

General information

Discoveror: Johann Gahn
Date discovered: 1774
Discovered at: Sweden
Meaning of name: From the Latin word "magnes" meaning "magnet", or "magnesia nigri" meaning "black magnesia" (MnO2)

Physical data

Standard state: solid at 298 K
Colour: silvery metallic
Density of solid at ambient temperature/kg m-3: 7470
Molar volume/cm3: 7.35

Radii /pm

Atomic: 161
Covalent (single bond):
Pauling radius for the ion [Mn]-: no data

Valence shell orbital radius maxima (Rmax)
orbital s p d f
radius141.9no data40.9no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 1.55
Allred Rochow: 1.60

Crystal Structure

structure: cubic

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

ball-and-stick.gif

Temperatures (/K)

melting point: 1519
boiling point: 2334

Enthalpies /kJ mol-1

fusion: 13.1
vaporization: 220

single bond enthalpies:
Mn-F Mn-Cl Mn-Br Mn-I Mn-Mn
no data no data no data 332.2 25.9

Ionization enthalpies /kJ mol-1

Number Enthalpy
1st717.4
2nd1509.1
3rd3248.4
4th4940
5th6990
6th9200
7th11508
8th18956

Isotopes

This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
55Mn54.9380471 (16)100

Further Information

Copyright 1997 Mark Winter
Department of Chemistry at the University of Sheffield, Sheffield S3 7HF, England.

The current version of this document is at http://www.shef.ac.uk/~chem/web-elements-I/Mn.html