Relative atomic mass: 54.938045 +- 0.000005

English: Manganese
French: Manganese
Croatian: Mangan
German: Mangan
Italian: Manganese
Spanish: Manganeso

Atomic number: 25
Group numbers: 7
Period: 4
Standard state (20 oC): solid

Discovery: 1774 Johan Gottlieb Gahn (SE)
Manganese was discovered by Johan Gottlieb Gahn (SE) in 1774. The origin of the name comes from the Latin word magnes meaning magnet, or magnesia nigri meaning black magnesia (MnO2). It is a hard, brittle, grey-white metal with a pinkish tinge. Impure forms are reactive and rust like iron in moist air. Manganese is most abundant ores are pyrolusite (MnO2), psilomelane [(Ba,H2O)2Mn5O10] and rhodochrosite (MnCO3). Pure metal is produced by mixing MnO2 with powered Al and ignited in a furnace. It's used in steel, batteries and ceramics. The steel in railroad tracks can contain as much as 1.2% manganese. It is crucial to the effectiveness of vitamin B1. The price of 99.9 % pure manganese pieces is 87.80 for 1000 g.
Electronic configuration: [Ar] 3d5 4s2
Formal oxidation number: +2 +3 +4 +7
Atomic radius: 136.7 pm

Electronegativities: 1.55
Thermal conductivity: 7.82 W/(m K)
Electrical resistivity (20 oC): 144 microOhm cm

Melting point: 1246 oC
Boiling point: 2061 oC

Heat of fusion: 14.4 kJ/mol
Heat of vaporization: 220.5 kJ/mol
Heat of atomization: 279.37 kJ/mol

24Cr <= 25Mn => 26Fe

ASCII Periodic Table of the Elements
29 Aug. 2017
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