Manganese

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Manganese
25Mn
-

Mn

Tc
chromiummanganeseiron
Appearance
silvery metallic
A rough fragment o lustrous silvery metal
General properties
Name, seembol, nummer manganese, Mn, 25
Pronunciation /ˈmæŋɡənz/ MANG-gə-neez
Element category transeetion metal
Group, period, block 7, 4, d
Staundart atomic wicht 54.938044(3)
Electron confeeguration [Ar] 4s2 3d5
2, 8, 13, 2
Electron shells of manganese (2, 8, 13, 2)
History
Discovery Torbern Olof Bergman (1770)
First isolation Johann Gottlieb Gahn (1774)
Physical properties
Phase solid
Density (near r.t.) 7.21 g·cm−3
Liquid density at m.p. 5.95 g·cm−3
Meltin pynt 1519 K, 1246 °C, 2275 °F
Boilin pynt 2334 K, 2061 °C, 3742 °F
Heat o fusion 12.91 kJ·mol−1
Heat o vaporization 221 kJ·mol−1
Molar heat capacity 26.32 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1228 1347 1493 1691 1955 2333
Atomic properties
Oxidation states 7, 6, 5, 4, 3, 2, 1, -1, -2, -3
(oxides: acidic, basic or amphoteric; depending on the oxidation state)
Electronegativity 1.55 (Pauling scale)
Ionization energies
(more)
1st: 717.3 kJ·mol−1
2nt: 1509.0 kJ·mol−1
3rd: 3248 kJ·mol−1
Atomic radius 127 pm
Covalent radius 139±5 (low spin), 161±8 (high spin) pm
Miscellanea
Crystal structure body-centered cubic
Manganese has a body-centered cubic crystal structure
Magnetic orderin paramagnetic
Electrical resistivity (20 °C) 1.44 µΩ·m
Thermal conductivity 7.81 W·m−1·K−1
Thermal expansion (25 °C) 21.7 µm·m−1·K−1
Speed of sound (thin rod) (20 °C) 5150 m·s−1
Young's modulus 198 GPa
Bulk modulus 120 GPa
Mohs hairdness 6.0
Brinell hairdness 196 MPa
CAS registry nummer 7439-96-5
Most stable isotopes
Main article: Isotopes o manganese
iso NA hauf-life DM DE (MeV) DP
52Mn syn 5.591 d ε - 52Cr
β+ 0.575 52Cr
γ 0.7, 0.9, 1.4 -
53Mn trace 3.74×106 y ε - 53Cr
54Mn syn 312.3 d ε 1.377 54Cr
γ 0.834 -
55Mn 100% 55Mn is stable wi 30 neutrons
· r

Manganese is a chemical element, designated bi the seembol Mn. It haes the atomic nummer 25. It is foond as a free element in naitur (eften in combination wi iron), an in mony minerals. Manganese is a metal wi important industrial metal alloy uises, particularly in stainless steels.

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