Manganese

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Manganese,  25Mn
A fragment o lustrous sillery metal
General properties
Appearance silvery metallic
Staundart atomic wecht (Ar, staundart) 54.938044(3)
Manganese in the periodic cairt
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 Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) 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 Gowd Mercur (element) Thallium Leid (element) 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 Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
-

Mn

Tc
chromiummanganeseiron
Atomic nummer (Z) 25
Group group 7
Period period 4
Element category   transition metal
Block d-block
Electron confeeguration [Ar] 4s2 3d5
Electrons per shell
2, 8, 13, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 1519 K ​(1246 °C, ​2275 °F)
Bylin pynt 2334 K ​(2061 °C, ​3742 °F)
Density (near r.t.) 7.21 g/cm3
when liquid (at m.p.) 5.95 g/cm3
Heat o fusion 12.91 kJ/mol
Heat o vapourisation 221 kJ/mol
Molar heat capacity 26.32 J/(mol·K)
Vapour pressur
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 Pauling scale: 1.55
Ionisation energies
Atomic radius empirical: 127 pm
Covalent radius 139±5 (low spin), 161±8 (high spin) pm
Color lines in a spectral range
Miscellanea
Creestal structurbody-centred cubic (bcc)
Body-centered cubic creestal structur for manganese
Speed o soond thin rod 5150 m/s (at 20 °C)
Thermal expansion 21.7 µm/(m·K) (at 25 °C)
Thermal conductivity 7.81 W/(m·K)
Electrical resistivity 1.44 µ Ω·m (at 20 °C)
Magnetic orderin paramagnetic
Young's modulus 198 GPa
Bouk modulus 120 GPa
Mohs haurdness 6.0
Brinell haurdness 196 MPa
CAS Nummer 7439-96-5
History
Diskivery Torbern Olof Bergman (1770)
First isolation Johann Gottlieb Gahn (1774)
Main isotopes o manganese
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 52Mn syn 5.591 d ε 52Cr
β+ 52Cr
γ -
53Mn trace 3.74×106 y ε 53Cr
54Mn syn 312.3 d ε 54Cr
γ -
55Mn 100% stable
| references | in Wikidata

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 meenerals. Manganese is a metal wi important industrial metal alloy uises, parteecularly in stainless steels.

Historically, manganese is named for pyrolusite an ither black meenerals frae the region o Magnesia in Greece, that an aw gae its name tae magnesium an the airn ure magnetite. Bi the mid-18th century, Swadish-German chemist Carl Wilhelm Scheele haed uised pyrolusite tae produce chlorine. Scheele an ithers war awaur that pyrolusite (nou kent tae be manganese dioxide) conteened a new element, but thay war unable tae isolate it. Johan Gottlieb Gahn wis the first tae isolate an impure saumple o manganese metal in 1774, that he did bi reducin the dioxide wi caurbon.

Manganese phosphating is uised for roust an corrosion prevention on steel. Ionised manganese is uised industrially as pigments o various colours, that depend on the oxidation state o the ions. The permanganates o alkali an alkaline yird metals are pouerfu oxidisers. Manganese dioxide is uised as the cathode (electron acceptor) material in zinc-carbon an alkaline batteries.

In biology, manganese(II) ions function as cofactors for a lairge variety o enzymes wi mony functions.[1] Manganese enzymes are pairteecularly essential in detoxification o superoxide free radicals in organisms that maun deal wi elemental oxygen. Manganese an aw functions in the oxygen-evolvin complex o photosynthetic plants. While the element is a required trace meeneral for aw kent leevin organisms, it an aw acts as a neurotoxin in lairger amoonts. Espeicially throu inhalation, it can cause manganism, a condeetion in mammals leadin tae neurological damage that is whiles irreversible.

References[eedit | eedit soorce]

  1. Roth, Jerome; Ponzoni, Silvia; Aschner, Michael (2013). "Chapter 6 Manganese Homeostasis and Transport". In Banci, Lucia. Metallomics and the Cell. Metal Ions in Life Sciences. 12. Springer. doi:10.1007/978-94-007-5561-1_6. ISBN 978-94-007-5560-4.  electronic-book ISBN 978-94-007-5561-1