Manganese

25
Mn
Group
7
Period
4
Block
d
Protons
Electrons
Neutrons
25
25
30
General Properties
Atomic Number
25
Atomic Weight
54.938045
Mass Number
55
Category
Transition metals
Colour
Silver
Radioactive
No
From the Latin word magnes, magnet, from magnetic properties of pyrolusite
Crystal Structure
Body Centered Cubic
History
By the mid-18th century, Swedish chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine.

Scheele and others were aware that pyrolusite contained a new element, but they were not able to isolate it.

Johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, by reducing the dioxide with carbon.
Electrons per shell
2, 8, 13, 2
Electron Configuration
[Ar] 3d5 4s2
Mn
Neanderthals may have used black manganese di oxide as a cosmetic 50,000 years ago
Physical Properties
Phase
Solid
Density
7.44 g/cm3
Melting Point
1519.15 K | 1246 °C | 2274.8 °F
Boiling Point
2334.15 K | 2061 °C | 3741.8 °F
Heat of Fusion
13.2 kJ/mol
Heat of Vaporization
220 kJ/mol
Specific Heat Capacity
0.479 J/g·K
Abundance in Earth's crust
0.11%
Abundance in Universe
0.0008%
Small
Image Credits: Images-of-elements
Small pieces of manganese
CAS Number
7439-96-5
PubChem CID Number
23930
Atomic Properties
Atomic Radius
127 pm
Covalent Radius
139 pm
Electronegativity
1.55 (Pauling scale)
Ionization Potential
7.434 eV
Atomic Volume
7.4 cm3/mol
Thermal Conductivity
0.0782 W/cm·K
Oxidation States
-3, -2, -1, 1, 2, 3, 4, 5, 6, 7
Applications
For over 2000 years, manganese dioxide has been used to make colourless glass.

Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries.

Manganese also functions in the oxygen-evolving complex of photosynthetic plants.

The dioxide is also used in the preparation of oxygen and chlorine and in drying black paints.
Excess manganese, particularly inhalation of the powder, is toxic
Isotopes
Stable Isotopes
55Mn
Unstable Isotopes
44Mn, 45Mn, 46Mn, 47Mn, 48Mn, 49Mn, 50Mn, 51Mn, 52Mn, 53Mn, 54Mn, 56Mn, 57Mn, 58Mn, 59Mn, 60Mn, 61Mn, 62Mn, 63Mn, 64Mn, 65Mn, 66Mn, 67Mn, 68Mn, 69Mn