Atomic number:25

Group numbers:7

Period:4

Electronic configuration:[Ar] 3d⁵ 4s²

Formal oxidation number:+2 +3 +4 +7

Electronegativities:1.55

Atomic radius / pm:136.7

Relative atomic mass:54.938045 ± 0.000005

 

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.

Density / g dm^-3:7440 (alpha, 293 K)

 6430 (m.p.)

Molar volume / cm³mol^-1:7.38 (alpha, 293 K)

 8.54 (m.p.)

Electrical resistivity / μΩcm:144 (20 °C)

Thermal conductivity / W m^-1K^-1:7.82

Melting point / °C:1246

Boiling point / °C:2061

Heat of fusion / kJ mol^-1:14.4

Heat of vaporization / kJ mol^-1:220.5

Heat of atomization / kJ mol^-1:279.37

1st ionization energy / kJ mol^-1:717.28

2nd ionization energy / kJ mol^-1:1509.04

3rd ionization energy / kJ mol^-1:3248.49

in the atmosphere / ppm:-

in the Earth's crust / ppm:1400

in the oceans / ppm:0.002