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**Characteristics of Manganese**:
Manganese is a silvery-gray metal resembling iron.
– It is hard, brittle, and easily oxidizes.
Manganese and its ions are paramagnetic.
Manganese tarnishes in air and rusts in water.
– Four allotropes of solid manganese are known, labeled α, β, γ, and δ.
Manganese slowly tarnishes in air and oxidizes like iron in water.

**Isotopes and Allotropes of Manganese**:
– Naturally occurring manganese has one stable isotope.
– Several radioisotopes of manganese have been identified.
– Mn decays to Cr with a half-life of 3.7 million years.
Manganese isotopic contents are used in isotope geology.
– Mn provides evidence for nucleosynthetic processes in the Solar System.
– Four allotropes of solid manganese are known, with alpha manganese being the equilibrium phase at room temperature.

**Chemical Compounds and Industrial Applications**:
– Common oxidation states of manganese are +2, +3, +4, +6, and +7.
– Potassium permanganate is a common laboratory reagent.
Manganese compounds have historical usage in glassmaking and were isolated by Johan Gottlieb Gahn.
Manganese is essential in iron and steel production for its properties.
Manganese alloyed with iron was found to be harder without increased brittleness.
Manganese was introduced to steelmaking by Robert Forester Mushet in 1856.

**Organomanganese Compounds**:
Manganese forms organometallic derivatives with Mn-C bonds in lower oxidation states.
– Mn is inexpensive and relatively low in toxicity, making it attractive in organometallic chemistry.
– The name ‘manganese’ has a complex origin from ancient times.
Manganese dioxide has been used as a pigment for cave paintings.
Manganese compounds have historical usage in glassmaking and were isolated by Johan Gottlieb Gahn.

**Occurrence and Historical Applications**:
Manganese is the 12th most abundant element in the Earth’s crust.
– Soil contains an average of 440ppm of manganese.
Manganese occurs mainly as pyrolusite, braunite, and rhodochrosite.
South Africa holds about 80% of the world’s known manganese resources.
Manganese dioxide was historically used in glassmaking, batteries, and as a pigment.

Manganese (Wikipedia)

Manganese is a chemical element; it has symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. Manganese is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. It improves strength, workability, and resistance to wear. Manganese oxide is used as an oxidising agent; as a rubber additive; and in glass making, fertilisers, and ceramics. Manganese sulfate can be used as a fungicide.

Manganese, 25Mn
A rough fragment of lustrous silvery metal
Pure manganese cube and oxidized manganese chips
Pronunciation/ˈmæŋɡənz/ (MANG-gə-neez)
Appearancesilvery metallic
Standard atomic weight Ar°(Mn)
  • 54.938043±0.000002
  • 54.938±0.001 (abridged)
Manganese in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


Atomic number (Z)25
Groupgroup 7
Periodperiod 4
Block  d-block
Electron configuration[Ar] 3d5 4s2
Electrons per shell2, 8, 13, 2
Physical properties
Phase at STPsolid
Melting point1519 K ​(1246 °C, ​2275 °F)
Boiling point2334 K ​(2061 °C, ​3742 °F)
Density (near r.t.)7.21 g/cm3
when liquid (at m.p.)5.95 g/cm3
Heat of fusion12.91 kJ/mol
Heat of vaporization221 kJ/mol
Molar heat capacity26.32 J/(mol·K)
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−3, −1, 0, +1, +2, +3, +4, +5, +6, +7 (depending on the oxidation state, an acidic, basic, or amphoteric oxide)
ElectronegativityPauling scale: 1.55
Ionization energies
  • 1st: 717.3 kJ/mol
  • 2nd: 1509.0 kJ/mol
  • 3rd: 3248 kJ/mol
  • (more)
Atomic radiusempirical: 127 pm
Covalent radiusLow spin: 139±5 pm
High spin: 161±8 pm
Color lines in a spectral range
Spectral lines of manganese
Other properties
Natural occurrenceprimordial
Crystal structureα-Mn: ​body-centered cubic (bcc) (cI58)
Lattice constant
Body-centered cubic crystal structure for α-Mn: manganese
a = 891.16 pm (at 20 °C)
Thermal expansion21.7 µm/(m⋅K) (at 25 °C)
Thermal conductivity7.81 W/(m⋅K)
Electrical resistivity1.44 µΩ⋅m (at 20 °C)
Magnetic orderingparamagnetic
Molar magnetic susceptibility(α) +529.0×10−6 cm3/mol (293 K)
Young's modulus198 GPa
Bulk modulus120 GPa
Speed of sound thin rod5150 m/s (at 20 °C)
Mohs hardness6.0
Brinell hardness196 MPa
CAS Number7439-96-5
DiscoveryCarl Wilhelm Scheele (1774)
First isolationJohann Gottlieb Gahn (1774)
Isotopes of manganese
Main isotopes Decay
abun­dance half-life (t1/2) mode pro­duct
52Mn synth 5.591 d β+ 52Cr
53Mn trace 3.7×106 y ε 53Cr
54Mn synth 312.081 d ε 54Cr
β 54Fe
β+ 54Cr
55Mn 100% stable
 Category: Manganese
| references

Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component in dozens of proteins and enzymes. It is found mostly in the bones, but also the liver, kidneys, and brain. In the human brain, the manganese is bound to manganese metalloproteins, most notably glutamine synthetase in astrocytes.

It is familiar in the laboratory in the form of the deep violet salt potassium permanganate. It occurs at the active sites in some enzymes. Of particular interest is the use of a Mn-O cluster, the oxygen-evolving complex, in the production of oxygen by plants.

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