Zinc

Zinc is a chemical element wi the seembol Zn an atomic nummer 30. It is the first element in group 12 o the periodic table. In some respects zinc is chemically seemilar tae magnesium: baith elements exhibit anly ane normal oxidation state (+2), an the Zn2+ an Mg2+ ions are o seemilar size. Zinc is the 24t maist abundant element in Yird's crust an haes five stable isotopes. The maist common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The lairgest workable lodes are in Australie, Asia, an the United States. Zinc is refined bi froth flotation o the ore, roasting, an final extraction uisin electricity (electrowinning).

Zinc, 30Zn
Template:Infobox element/symbol-to-top-image/alt
Zinc
Appearancesiller-gray
Standard atomic weight Ar, std(Zn)65.38(2)[1]
Zinc in the periodic cairt
HydrogenHelium
LithiumBerylliumBoronCarbonNitrogenOxygenFluorineNeon
SodiumMagnesiumAluminiumSiliconPhosphorusSulfurChlorineArgon
PotassiumCalciumScandiumTitaniumVanadiumChromiumManganeseAirnCobaltNickelCapperZincGalliumGermaniumArsenicSeleniumBromineKrypton
RubidiumStrontiumYttriumZirconiumNiobiumMolybdenumTechnetiumRutheniumRhodiumPalladiumSiller (element)CadmiumIndiumTinAntimonyTelluriumIodineXenon
CaesiumBariumLanthanumCeriumPraseodymiumNeodymiumPromethiumSamariumEuropiumGadoliniumTerbiumDysprosiumHolmiumErbiumThuliumYtterbiumLutetiumHafniumTantalumTungstenRheniumOsmiumIridiumPlatinumGowdMercur (element)ThalliumLeid (element)BismuthPoloniumAstatineRadon
FranciumRadiumActiniumThoriumProtactiniumUraniumNeptuniumPlutoniumAmericiumCuriumBerkeliumCaliforniumEinsteiniumFermiumMendeleviumNobeliumLawrenciumRutherfordiumDubniumSeaborgiumBohriumHassiumMeitneriumDarmstadtiumRoentgeniumCoperniciumUnuntriumFleroviumUnunpentiumLivermoriumUnunseptiumUnunoctium
-

Zn

Cd
copperzincgallium
Atomic nummer (Z)30
Groupgroup 12
Periodperiod 4
Blockd-block
Element category  Post-transeetion metal
Electron confeeguration[Ar] 3d10 4s2
Electrons per shell2, 8, 18, 2
Pheesical properties
Phase at STPsolit
Meltin pynt692.68 K ​(419.53 °C, ​787.15 °F)
Bylin pynt1180 K ​(907 °C, ​1665 °F)
Density (near r.t.)7.14 g/cm3
when liquid (at m.p.)6.57 g/cm3
Heat o fusion7.32 kJ/mol
Heat o vapourisation123.6 kJ/mol
Molar heat capacity25.470 J/(mol·K)
Vapour pressur
P (Pa)1101001 k10 k100 k
at T (K)6106707508529901179
Atomic properties
Oxidation states−2, 0, +1, +2 (an amphoteric oxide)
ElectronegativityPauling scale: 1.65
Ionisation energies
  • (more)
Atomic radiusempirical: 134 pm
Covalent radius122±4 pm
Van der Waals radius139 pm
Colour lines in a spectral range
Colour lines in a spectral range
Spectral lines o zinc
Ither properties
Naitural occurrenceprimordial
Creestal structur ​hexagonal close-packed (hcp)
Hexagonal close packed creestal structur for zinc
Speed o soond thin rod(rolled) 3850 m/s (at r.t.)
Thermal expansion30.2 µm/(m·K) (at 25 °C)
Thermal conductivity116 W/(m·K)
Electrical resistivity59.0 n Ω·m (at 20 °C)
Magnetic orderindiamagnetic
Young's modulus108 GPa
Shear modulus43 GPa
Bulk modulus70 GPa
Poisson ratio0.25
Mohs haurdness2.5
Brinell haurdness412 MPa
CAS Nummer7440-66-6
History
DiskiveryIndian metallurgists (before 1000 BC)
First isolationAndreas Sigismund Marggraf (1746)
Recognized as a unique metal biRasaratna Samuccaya (800)
Main isotopes o zinc
Iso­topeAbun­danceHauf-life (t1/2)Decay modePro­duct
64Zn48.6%>2.3×1018 y+β+)64Ni
65Znsyn243.8 dε65Cu
γ-
66Zn27.9%stable
67Zn4.1%stable
68Zn18.8%stable
69Znsyn56 minβ69Ga
69mZnsyn13.76 hβ69Ga
70Zn0.6%>1.3×1016 yβ)70Ge
71Znsyn2.4 minβ71Ga
71mZnsyn3.97 dβ71Ga
72Znsyn46.5 hβ72Ga
Decay modes in parentheses are predictit, but hae nae yet been observed
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Bress, an alloy o capper an zinc in various proportions, wis uised as early as the third millennium BC in the Aegean, Iraq, the Unitit Arab Emirates, Kalmykia, Turkmenistan an Georgia, an the seicont millennium BC in West India, Uzbekistan, Iran, Sirie, Iraq, an Israel[2] (Judea[3]).[4] Zinc metal wis nae produced on a lairge scale until the 12t century in India an wis unkent tae Europe until the end o the 16t century. The mines o Rajasthan hae gien definite evidence o zinc production going back tae the 6t century BC.[5] Tae date, the auldest evidence o pure zinc comes frae Zawar, in Rajasthan, as early as the 9t century AD when a distillation process wis employed tae mak pure zinc.[6] Alchemists burned zinc in air tae form what thay cried "philosopher's wool" or "white snow".

The element wis probably named bi the alchemist Paracelsus efter the German wird Zinke (prong, tuith). German chemist Andreas Sigismund Marggraf is credited wi discovering pure metallic zinc in 1746. Wirk bi Luigi Galvani an Alessandro Volta uncovered the electrochemical properties o zinc bi 1800. Corrosion-reseestant zinc plating o iron (het-dip galvanisin) is the major application for zinc. Ither applications are in electrical batteries, smaw non-structural castins, an alloys sic as bress. A variety o zinc compoonds are commonly uised, sic as zinc carbonate an zinc gluconate (as dietary supplements), zinc chloride (in deodorants), zinc pyrithione (anti-fousk shampoos), zinc sulfide (in luminescent paints), an zinc methyl or zinc diethyl in the organic laboratory.

Zinc is an essential meeneral perceived bi the public the day as bein o "exceptional biologic and public health importance", especially regarding prenatal an postnatal development.[7] Zinc deficiency affects aboot twa billion fowk in the developin warld an is associated wi mony diseases.[8] In childer, deficiency causes growthe retardation, delayed sexual maturation, infection susceptibility, an diarrhea.[7] Enzymes wi a zinc atom in the reactive centre are widespread in biochemistry, sic as alcohol dehydrogenase in humans.[9] Consumption o excess zinc can cause ataxia, lethargy an capper deficiency.

References