(From the Italian manganese) A grayish-white, metallic chemical element, usually hard and brittle, which rusts like iron but is not magnetic. It is used in the manufacture of alloys of iron, aluminum, and copper.

Symbol: Mn
Atomic number: 25
Atomic weight: 54.938049
Density (at room temperature and pressure): 7.4 g/cc
Melting point: 1,246°C
Boiling point: 2,061°C
Valence: +2, +3, +4, +7
Ground state electron configuration: [Ar]3d54s2

Symbol: Mn
Atomic Number: 25
Boiling Point: 2235 K
Melting Point: 1518 K
Density at 300K: 7.44 g/cm3
Covalent radius: 1.17
Atomic radius: 1.79
Atomic volume: 7.39 cm3/mol
First ionization potental: 7.435 V
Specific heat capacity: 0.48 Jg-1K-1
Thermal conductivity: 7.82 Wm-1K-1
Electrical conductivity: 0.5 106Ω-1m-1
Heat of fusion: 14.64 kJ/mol
Heat of vaporization: 219.74 kJ/mol
Electronegativity: 1.55 (Pauling's)

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Man`ga*nese" (?), n. [F. manganese, It. mamaganese, sasso magnesio; prob. corrupted from L. magnes, because of its resemblance to the magnet. See Magnet, and cf. Magnesia.] Chem.

An element obtained by reduction of its oxide, as a hard, grayish white metal, fusible with difficulty, but easily oxidized. Its ores occur abundantly in nature as the minerals pyrolusite, manganite, etc. Symbol Mn. Atomic weight 54.8.

⇒ An alloy of manganese with iron (called ferromanganese) is used to increase the density and hardness of steel.

Black oxide of manganese, Manganese dioxide ∨ peroxide, ∨ Black manganese Chem., a heavy black powder MnO2, occurring native as the mineral pyrolusite, and valuable as a strong oxidizer; -- called also familiarly manganese. It colors glass violet, and is used as a decolorizer to remove the green tint of impure glass. Manganese bronze, an alloy made by adding from one to two per cent of manganese to the copper and zinc used in brass.


© Webster 1913.

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