View source for Zinc

{{About|the chemical element}}
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{{Infobox zinc}}
'''Zinc''' is a [[chemical element]] with the [[Symbol (chemistry)|symbol]] '''Zn''' and atomic number 30. It is a slightly brittle metal at [[room temperature]] and has a shiny-greyish appearance when oxidation is removed. It is the first element in [[group 12 element|group 12 (IIB)]] of the [[periodic table]]. In some respects, zinc is chemically similar to [[magnesium]]: both elements exhibit only one normal oxidation state (+2), and the Zn<sup>2+</sup> and Mg<sup>2+</sup> [[ion]]s are of similar size.{{efn|The elements are from different metal groups. See periodic table.}} Zinc is the 24th most abundant [[Abundance of elements in Earth's crust|element in Earth's crust]] and has five stable [[isotope]]s. The most common zinc [[ore]] is [[sphalerite]] (zinc blende), a [[zinc sulfide]] mineral. The largest workable [[lode]]s are in Australia, Asia, and the United States. Zinc is refined by [[froth flotation]] of the ore, [[Roasting (metallurgy)|roasting]], and final [[extractive metallurgy|extraction]] using [[electricity]] ([[electrowinning]]).
Zinc is an essential [[trace element]] for humans,<ref name="Maret-2013" /><ref name="Zinc - brain disorders 2015 review" /><ref name="Zinc & sleep 2017 review" /> animals,<ref name="Prasad-2008" /> plants<ref name="Broadley2007" /> and for [[microorganism]]s<ref name="Sugarman-1983" /> and is necessary for prenatal and postnatal development.<ref name="Hambridge2007">{{Cite journal |author=Hambidge, K. M. |author2=Krebs, N. F. |name-list-style=amp |date=2007 |title=Zinc deficiency: a special challenge |journal=J. Nutr. |volume=137 |issue=4 |pages=1101–5 |doi=10.1093/jn/137.4.1101 |pmid=17374687 |doi-access=free}}</ref> It is the second most abundant trace metal in humans after iron and it is the only metal which appears in all [[Enzyme#Classification and nomenclature|enzyme classes]].<ref name="Broadley2007" /><ref name="Zinc & sleep 2017 review" /> Zinc is also an essential nutrient element for coral growth as it is an important cofactor for many enzymes.<ref>{{Cite journal |last1=Xiao |first1=Hangfang |last2=Deng |first2=Wenfeng |last3=Wei |first3=Gangjian |last4=Chen |first4=Jiubin |last5=Zheng |first5=Xinqing |last6=Shi |first6=Tuo |last7=Chen |first7=Xuefei |last8=Wang |first8=Chenying |last9=Liu |first9=Xi |date=October 30, 2020 |title=A Pilot Study on Zinc Isotopic Compositions in Shallow-Water Coral Skeletons |url=https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GC009430#:~:text=Although%20excess%20Zn%20is%20toxic,of%20zooxanthellae%20and%20calcification%20of |journal=Geochemistry, Geophysics, Geosystems|volume=21 |issue=11 |doi=10.1029/2020GC009430 |bibcode=2020GGG....2109430X |s2cid=228975484 }}</ref>
[[Zinc deficiency]] affects about two billion people in the developing world and is associated with many diseases.<ref name="Prasad2003" /> In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, and [[diarrhea]].<ref name="Hambridge2007" /> [[Enzyme]]s with a zinc atom in the [[prosthetic groups|reactive center]] are widespread in biochemistry, such as [[alcohol dehydrogenase]] in humans.<ref>{{cite book |last1=Maret |first1=Wolfgang |chapter=Zinc and the Zinc Proteome |title=Metallomics and the Cell |date=2013 |publisher=Springer |isbn=978-94-007-5561-1 |editor1-last=Banci |editor1-first=Lucia |series=Metal Ions in Life Sciences |volume=12 |pages=479–501 |doi=10.1007/978-94-007-5561-1_14 |pmid=23595681}}
</ref> Consumption of excess zinc may cause [[ataxia]], [[lethargy]], and [[copper deficiency]]. In marine biomes, notably within polar regions, a deficit of zinc can compromise the vitality of primary algal communities, potentially destabilizing the intricate marine trophic structures and consequently impacting biodiversity.<ref>{{Cite web |last=Anglia |first=University of East |title=Zinc vital to evolution of complex life in polar oceans |url=https://phys.org/news/2022-06-zinc-vital-evolution-complex-life.html |access-date=2023-09-03 |website=phys.org |language=en}}</ref>
[[Brass]], an [[alloy]] of [[copper]] and zinc in various proportions, was used as early as the third millennium BC in the [[Aegean Sea|Aegean]] area and the region which currently includes [[Iraq]], the [[United Arab Emirates]], [[Kalmykia]], [[Turkmenistan]] and [[Georgia (country)|Georgia]]. In the second millennium BC it was used in the regions currently including [[West India]], [[Uzbekistan]], [[Iran]], [[Syria]], Iraq, and [[Israel]].<ref>{{Cite book|url=http://www.safarmer.com/Indo-Eurasian/Brass2007.pdf|title=Of brass and bronze in prehistoric Southwest Asia|last=Thornton|first=C. P.|date=2007|publisher=Archetype Publications|isbn=978-1-904982-19-7|url-status=live|archive-url=https://web.archive.org/web/20150924093433/http://www.safarmer.com/Indo-Eurasian/Brass2007.pdf|archive-date=September 24, 2015}}</ref><ref name="Greenwood1997p1201" /><ref name="jas5" /> Zinc [[metal]] was not produced on a large scale until the 12th century in India, though it was known to the ancient Romans and Greeks.<ref>{{Cite web|url=https://www.rsc.org/periodic-table/element/30/zinc | title=Zinc – Royal Society Of Chemistry | url-status=live|archive-url=https://web.archive.org/web/20170711095949/http://www.rsc.org/periodic-table/element/30/zinc | archive-date=July 11, 2017}}</ref> The mines of [[Rajasthan]] have given definite evidence of zinc production going back to the 6th century BC.<ref>{{cite web |url=http://www.infinityfoundation.com/mandala/t_es/t_es_agraw_zinc_frameset.htm |title=India Was the First to Smelt Zinc by Distillation Process |publisher=Infinityfoundation.com |access-date=April 25, 2014 |url-status=live |archive-url=http://arquivo.pt/wayback/20160516192708/http://www.infinityfoundation.com/mandala/t_es/t_es_agraw_zinc_frameset.htm |archive-date=May 16, 2016 }}</ref> The oldest evidence of pure zinc comes from Zawar, in Rajasthan, as early as the 9th century AD when a distillation process was employed to make pure zinc.<ref>{{cite journal |author=Kharakwal, J. S. |author2=Gurjar, L. K. |name-list-style=amp |title=Zinc and Brass in Archaeological Perspective |journal=Ancient Asia |date=December 1, 2006 |volume=1 |pages=139–159 |doi=10.5334/aa.06112 |doi-access=free }}</ref> [[alchemy|Alchemists]] burned zinc in air to form what they called "[[philosopher's wool]]" or "white snow".
The element was probably named by the alchemist [[Paracelsus]] after the German word ''Zinke'' (prong, tooth). German chemist [[Andreas Sigismund Marggraf]] is credited with discovering pure metallic zinc in 1746. Work by [[Luigi Galvani]] and [[Alessandro Volta]] uncovered the electrochemical properties of zinc by 1800. [[Corrosion]]-resistant [[galvanization|zinc plating]] of iron ([[hot-dip galvanizing]]) is the major application for zinc. Other applications are in electrical [[Zinc–carbon battery|batteries]], small non-structural castings, and alloys such as brass. A variety of zinc compounds are commonly used, such as [[zinc carbonate]] and [[zinc gluconate]] (as dietary supplements), [[zinc chloride]] (in deodorants), [[zinc pyrithione]] (anti-[[dandruff]] shampoos), zinc sulfide (in luminescent paints), and [[dimethylzinc]] or [[diethylzinc]] in the organic laboratory.
==Characteristics==
===Physical properties===
Zinc is a bluish-white, lustrous, [[diamagnetic]] metal,<ref name="CRCp4-41" /> though most common commercial grades of the metal have a dull finish.<ref name="Heiserman1992p123">{{harvnb|Heiserman|1992|p=123}}</ref> It is somewhat less dense than [[iron]] and has a hexagonal [[crystal structure]], with a distorted form of [[Close-packing of equal spheres|hexagonal close packing]], in which each atom has six nearest neighbors (at 265.9 pm) in its own plane and six others at a greater distance of 290.6 pm.<ref>Wells A.F. (1984) ''Structural Inorganic Chemistry'' 5th edition p 1277 Oxford Science Publications {{ISBN|0-19-855370-6}}</ref> The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150&nbsp;°C.<ref name="CRCp4-41" /><ref name="Heiserman1992p123" /> Above 210&nbsp;°C, the metal becomes brittle again and can be pulverized by beating.<ref>{{Cite book|url=https://books.google.com/books?id=SSkKAAAAIAAJ|title=The Useful Metals and Their Alloys|first=John|last=Scoffern|author-link=John Scoffern|publisher=Houlston and Wright|date=1861|pages=591–603|access-date=April 6, 2009}}</ref> Zinc is a fair [[electrical conductivity|conductor of electricity]].<ref name="CRCp4-41" /> For a metal, zinc has relatively low melting (419.5&nbsp;°C) and boiling point (907&nbsp;°C).<ref name="ZincMetalProps">{{cite web|url=http://www.galvanizeit.org/design-and-fabrication/design-considerations/zinc-metal-properties |title=Zinc Metal Properties |publisher=American Galvanizers Association |date=2008 |access-date=April 7, 2015 |archive-url=https://web.archive.org/web/20150328205508/http://www.galvanizeit.org/design-and-fabrication/design-considerations/zinc-metal-properties |archive-date=March 28, 2015 |url-status=live }}</ref> The melting point is the lowest of all the [[d-block]] metals aside from [[mercury (element)|mercury]] and [[cadmium]]; for this reason among others, zinc, cadmium, and mercury are often not considered to be [[transition metal]]s like the rest of the d-block metals.<ref name="ZincMetalProps" />
Many [[alloy]]s contain zinc, including brass. Other metals long known to form binary alloys with zinc are [[aluminium]], [[antimony]], [[bismuth]], [[gold]], iron, [[lead]], mercury, [[silver]], [[tin]], [[magnesium]], [[cobalt]], [[nickel]], [[tellurium]], and [[sodium]].<ref>{{Cite journal|title=Production and Properties of Zinc: A Treatise on the Occurrence and Distribution of Zinc Ore, the Commercial and Technical Conditions Affecting the Production of the Spelter, Its Chemical and Physical Properties and Uses in the Arts, Together with a Historical and Statistical Review of the Industry|last=Ingalls|first=Walter Renton|journal=The Engineering and Mining Journal|date=1902|pages=142–6|url=https://books.google.com/books?id=RhNDAAAAIAAJ&pg=PA133}}</ref> Although neither zinc nor [[zirconium]] is [[Ferromagnetism|ferromagnetic]], their alloy, {{chem|ZrZn|2}}, exhibits ferromagnetism below 35&nbsp;[[Kelvin|K]].<ref name="CRCp4-41" />
===Occurrence===
{{See also|:Category:Zinc minerals|l1=Zinc minerals}}
Zinc makes up about 75&nbsp;[[Parts per million|ppm]]&nbsp;(0.0075%) of [[Earth's crust]], making it the 24th most abundant element.<ref>{{Cite book |last=Emsley |first=John |url=https://books.google.com/books?id=2EfYXzwPo3UC&q=24th+most+abundant+element&pg=PA626 |title=Nature's Building Blocks: An A-Z Guide to the Elements |date=2011-08-25 |publisher=OUP Oxford |isbn=978-0-19-960563-7 |language=en}}</ref> It also makes up 312 ppm of the solar system, where it is the 22nd most abundant element.<ref>{{Citation |last=Brugger |first=Joël |title=Zinc |date=2018-07-18 |encyclopedia=Encyclopedia of Geochemistry: A Comprehensive Reference Source on the Chemistry of the Earth |series=Encyclopedia of Earth Sciences Series |pages=1521–1524 |url=https://research.monash.edu/en/publications/zinc |access-date=2024-06-21 |publisher=Springer |doi=10.1007/978-3-319-39312-4_212 |isbn=978-3-319-39311-7 |language=English}}</ref> Typical background concentrations of zinc do not exceed 1 μg/m<sup>3</sup> in the atmosphere; 300&nbsp;mg/kg in soil; 100&nbsp;mg/kg in vegetation; 20 μg/L in freshwater and 5 μg/L in seawater.<ref>{{Cite book|last=Rieuwerts|first=John|url=https://www.worldcat.org/oclc/886492996|title=The Elements of Environmental Pollution|publisher=Earthscan Routledge|year=2015|isbn=978-0-415-85919-6|location=London and New York|pages=286|oclc=886492996}}</ref> The element is normally found in association with other [[base metal]]s such as [[copper]] and [[lead]] in [[ore]]s.<ref name="Lehto1968p822" /> Zinc is a [[Goldschmidt classification#Chalcophile elements|chalcophile]], meaning the element is more likely to be found in minerals together with [[sulfur]] and other heavy [[chalcogen]]s, rather than with the light chalcogen [[oxygen]] or with non-chalcogen electronegative elements such as the [[halogen]]s. [[Sulfide]]s formed as the crust solidified under the [[redox|reducing]] conditions of the early Earth's atmosphere.<ref name="Greenwood1997p1202">{{harvnb|Greenwood|Earnshaw|1997|p=1202}}</ref> [[Sphalerite]], which is a form of zinc sulfide, is the most heavily mined zinc-containing ore because its concentrate contains 60–62% zinc.<ref name="Lehto1968p822" />
Other source minerals for zinc include [[smithsonite]] (zinc [[carbonate]]), [[hemimorphite]] (zinc [[silicate]]), [[wurtzite]] (another zinc sulfide), and sometimes [[hydrozincite]] (basic [[zinc carbonate]]).<ref name="Emsley2001p502" /> With the exception of wurtzite, all these other minerals were formed by weathering of the primordial zinc sulfides.<ref name="Greenwood1997p1202" />
Identified world zinc resources total about 1.9–2.8&nbsp;billion [[tonne]]s.<ref name="USGSMCS2015">{{cite web|last=Sai Srujan|first=A.V|date=2021|title=Mineral Commodity Summaries 2021: Zinc|url=https://pubs.usgs.gov/periodicals/mcs2021/mcs2021-zinc.pdf|access-date=June 21, 2021|publisher=[[United States Geological Survey]]}}</ref><ref>{{cite journal|last1=Erickson|first1=R. L.|title=Crustal Abundance of Elements, and Mineral Reserves and Resources|journal=U.S. Geological Survey Professional Paper |issue=820|date=1973|pages=21–25}}</ref> Large deposits are in Australia, Canada and the United States, with the largest reserves in [[Iran]].<ref name="Greenwood1997p1202" /><ref>{{cite web|url=http://www.etdb.org/StrategiesAndResearch/Countries/CSPReports/ReportsLibrary/CPS%20Report%20-%20Islamic%20Republic%20of%20Iran.doc |title=Country Partnership Strategy—Iran: 2011–12 |access-date=June 6, 2011 |publisher=ECO Trade and development bank |url-status=dead |archive-url=https://web.archive.org/web/20111026135641/http://www.etdb.org/StrategiesAndResearch/Countries/CSPReports/ReportsLibrary/CPS%20Report%20-%20Islamic%20Republic%20of%20Iran.doc |archive-date=October 26, 2011 }}</ref><ref>{{cite web|url=http://www.iranconmin.de/en/leftnavigation/market|title=IRAN&nbsp;– a growing market with enormous potential|access-date=March 3, 2010|publisher=IMRG|date=July 5, 2010|url-status=live|archive-url=https://web.archive.org/web/20130217181730/http://www.iranconmin.de/en/leftnavigation/market|archive-date=February 17, 2013}}</ref> The most recent estimate of reserve base for zinc (meets specified minimum physical criteria related to current mining and production practices) was made in 2009 and calculated to be roughly 480 Mt.<ref name="USGSMCS2009">{{cite web|last=Tolcin|first=A. C.|date=2009|url=http://minerals.usgs.gov/minerals/pubs/commodity/zinc/mcs-2015-zinc.pdf|publisher=[[United States Geological Survey]]|access-date=August 4, 2016|title=Mineral Commodity Summaries 2009: Zinc|url-status=live|archive-url=https://web.archive.org/web/20160702053035/http://minerals.usgs.gov/minerals/pubs/commodity/zinc/mcs-2015-zinc.pdf|archive-date=July 2, 2016}}</ref> Zinc reserves, on the other hand, are geologically identified ore bodies whose suitability for recovery is economically based (location, grade, quality, and quantity) at the time of determination. Since exploration and mine development is an ongoing process, the amount of zinc reserves is not a fixed number and sustainability of zinc ore supplies cannot be judged by simply extrapolating the combined mine life of today's zinc mines. This concept is well supported by data from the United States Geological Survey (USGS), which illustrates that although refined zinc production increased 80% between 1990 and 2010, the reserve lifetime for zinc has remained unchanged. About 346 million tonnes have been extracted throughout history to 2002, and scholars have estimated that about 109–305&nbsp;million tonnes are in use.<ref>{{Cite journal|last=Gordon|first=R. B.|author2=Bertram, M. |author3=Graedel, T. E. |title=Metal stocks and sustainability|journal=Proceedings of the National Academy of Sciences|volume=103|date=2006|pmid=16432205|pmc=1360560|doi=10.1073/pnas.0509498103|issue=5|bibcode = 2006PNAS..103.1209G|pages=1209–14 |doi-access=free}}</ref><ref>{{cite journal|last1=Gerst|first1=Michael|title=In-Use Stocks of Metals: Status and Implications|journal=Environmental Science and Technology|date=2008|volume=42|issue=19|pages=7038–45|doi=10.1021/es800420p|pmid=18939524|bibcode=2008EnST...42.7038G}}</ref><ref>{{cite journal|last1=Meylan|first1=Gregoire|title=The anthropogenic cycle of zinc: Status quo and perspectives|journal=Resources, Conservation and Recycling|volume=123|date=2016|pages=1–10|doi=10.1016/j.resconrec.2016.01.006}}</ref>
[[File:Sphalerite4.jpg|thumb|[[Sphalerite]] (ZnS)|alt=A black shiny lump of solid with uneven surface]]
===Isotopes===
{{Main|Isotopes of zinc}}
Five stable [[isotope]]s of zinc occur in nature, with <sup>64</sup>Zn being the most abundant isotope (49.17% [[natural abundance]]).<ref name="NNDC">{{cite web|url=http://www.nndc.bnl.gov/chart/|editor=Alejandro A. Sonzogni (Database Manager)|title=Chart of Nuclides|publisher=National Nuclear Data Center, [[Brookhaven National Laboratory]]|access-date=September 13, 2008|date=2008|location=Upton (NY)|url-status=live|archive-url=https://web.archive.org/web/20080522125027/http://www.nndc.bnl.gov/chart|archive-date=May 22, 2008}}</ref>{{NUBASE2016|ref}} The other isotopes found in nature are {{chem|66|Zn}} (27.73%), {{chem|67|Zn}} (4.04%), {{chem|68|Zn}} (18.45%), and {{chem|70|Zn}} (0.61%).{{NUBASE2016|name}}
Several dozen [[radioisotope]]s have been characterized. {{chem|65|Zn}}, which has a half-life of 243.66&nbsp;days, is the least active radioisotope, followed by {{chem|72|Zn}} with a half-life of 46.5&nbsp;hours.<ref name="NNDC" /> Zinc has 10 [[nuclear isomer]]s, of which <sup>69m</sup>Zn has the longest half-life, 13.76 h.<ref name="NNDC" /> The superscript ''m'' indicates a [[metastable]] isotope. The nucleus of a metastable isotope is in an [[excited state]] and will return to the [[ground state]] by emitting a [[photon]] in the form of a [[gamma ray]]. {{chem|61|Zn}} has three excited metastable states and {{chem|73|Zn}} has two.<ref>{{NUBASE 2003}}</ref> The isotopes {{chem|65|Zn}}, {{chem|71|Zn}}, {{chem|77|Zn}} and {{chem|78|Zn}} each have only one excited metastable state.<ref name="NNDC" />
The most common [[decay mode]] of a [[radioisotope]] of zinc with a [[mass number]] lower than 66 is [[electron capture]]. The [[decay product]] resulting from electron capture is an isotope of copper.<ref name="NNDC" />
:{{nuclide|zinc|n}} + {{SubatomicParticle|link=yes|electron}} → {{nuclide|copper|n}} + {{SubatomicParticle|link=yes|Electron neutrino}}
The most common decay mode of a radioisotope of zinc with mass number higher than 66 is [[beta decay]] (β<sup>−</sup>), which produces an isotope of [[gallium]].<ref name="NNDC" />
:{{nuclide|zinc|n}} → {{nuclide|gallium|n}} + {{SubatomicParticle|electron}} + {{SubatomicParticle|link=yes|Electron antineutrino}}
==Compounds and chemistry==
{{Main|Zinc compounds}}
===Reactivity===
{{see also|Clemmensen reduction}}
Zinc has an [[electron configuration]] of [Ar]3d<sup>10</sup>4s<sup>2</sup> and is a member of the [[group 12 element|group 12]] of the [[periodic table]]. It is a moderately reactive [[metal]] and strong [[reducing agent]].<ref name="CRC2006p8-29">{{harvnb|CRC|2006|pp='''8'''–29}}</ref> The surface of the pure metal [[tarnish]]es quickly, eventually forming a protective [[Passivation (chemistry)|passivating]] layer of the basic [[Hydrozincite|zinc carbonate]], {{chem|Zn|5|(OH)|6|(CO<sub>3</sub>)|2}}, by reaction with atmospheric [[carbon dioxide]].<ref>{{Cite book|publisher=CRC Press|date=1994|page=121|isbn=978-0-8247-9213-8|title=Corrosion Resistance of Zinc and Zinc Alloys| first=Frank C.|last=Porter}}</ref>
Zinc burns in air with a bright bluish-green flame, giving off fumes of [[zinc oxide]].<ref name="Holl" /> Zinc reacts readily with [[acid]]s, [[alkali]]s and other non-metals.<ref>{{Cite book|last=Hinds|first=John Iredelle Dillard|title=Inorganic Chemistry: With the Elements of Physical and Theoretical Chemistry|publisher=John Wiley & Sons|location=New York|date=1908|edition=2nd|pages=506–508|url=https://books.google.com/books?id=xMUMAAAAYAAJ}}</ref> Extremely pure zinc reacts only slowly at [[room temperature]] with acids.<ref name="Holl" /> Strong acids, such as [[hydrochloric acid|hydrochloric]] or [[sulfuric acid]], can remove the passivating layer and the subsequent reaction with the acid releases hydrogen gas.<ref name="Holl" />
The chemistry of zinc is dominated by the +2 oxidation state. When compounds in this oxidation state are formed, the outer [[electron shell|shell]] ''s'' electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d<sup>10</sup>.<ref>{{Cite book|last=Ritchie|first=Rob|title=Chemistry|publisher=Letts and Lonsdale|date=2004|edition=2nd|page=71|isbn=978-1-84315-438-9|url=https://books.google.com/books?id=idT9j6406gsC}}</ref> In aqueous solution an octahedral complex, {{chem|[Zn(H|2|O)<sub>6</sub>]|2+}} is the predominant species.<ref>{{Cite book|last=Burgess|first=John|title=Metal ions in solution|publisher=Ellis Horwood|location=New York|date=1978|page=147|isbn=978-0-470-26293-1}}</ref> The [[volatilization]] of zinc in combination with zinc chloride at temperatures above 285&nbsp;°C indicates the formation of {{chem|Zn|2|Cl|2}}, a zinc compound with a +1 oxidation state.<ref name="Holl" /> No compounds of zinc in positive oxidation states other than +1 or +2 are known.<ref>{{Cite book|last=Brady|first=James E.|author2=Humiston, Gerard E.|author3=Heikkinen, Henry|title=General Chemistry: Principles and Structure|publisher=John Wiley & Sons|date=1983|edition=3rd|page=[https://archive.org/details/generalchemistry1982brad/page/671 671]|isbn=978-0-471-86739-5|url=https://archive.org/details/generalchemistry1982brad/page/671}}</ref> Calculations indicate that a zinc compound with the oxidation state of +4 is unlikely to exist.<ref>{{Cite journal|journal=Inorganic Chemistry|date=1994|volume=33|issue=10|pages=2122–2131|title=Oxidation state +IV in group 12 chemistry. Ab initio study of zinc(IV), cadmium(IV), and mercury(IV) fluorides|author=Kaupp M.|author2=Dolg M.|author3=Stoll H.|author4=Von Schnering H. G.|doi=10.1021/ic00088a012|url=https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-60018}}</ref> Zn(III) is predicted to exist in the presence of strongly electronegative trianions;<ref>{{cite journal |last1=Samanta |first1=Devleena |last2=Jena |first2=Puru |title=Zn in the +III Oxidation State |url=https://pubs.acs.org/doi/abs/10.1021/ja3029119# |journal=Journal of the American Chemical Society |date=2012|volume=134 |issue=20 |pages=8400–8403 |doi=10.1021/ja3029119 |pmid=22559713 }}</ref> however, there exists some doubt around this possibility.<ref>{{cite journal |last1=Schlöder |first1=Tobias |display-authors=etal |title=Can Zinc Really Exist in Its Oxidation State +III? |url=https://pubs.acs.org/doi/10.1021/ja3052409# |journal=Journal of the American Chemical Society |date=2012|volume=134 |issue=29 |pages=11977–11979 |doi=10.1021/ja3052409 |pmid=22775535 }}</ref> But in 2021 another compound was reported with more evidence that had the oxidation state of +3 with the formula ZnBeB<sub>11</sub>(CN)<sub>12</sub>.<ref>{{cite journal |last1=Fang |first1=Hong |last2=Banjade |first2=Huta |last3=Deepika |last4=Jena |first4=Puru |title=Realization of the Zn3+ oxidation state |journal=Nanoscale |date=2021|volume=13 |issue=33 |pages=14041–14048 |doi=10.1039/D1NR02816B |pmid=34477685 |s2cid=237400349 |doi-access=free }}</ref>
Zinc chemistry is similar to the chemistry of the late first-row transition metals, [[nickel]] and copper, though it has a filled d-shell and compounds are [[diamagnetic]] and mostly colorless.<ref name="Greenwood1997p1206" /> The [[ionic radii]] of zinc and magnesium happen to be nearly identical. Because of this some of the equivalent salts have the same [[crystal structure]],<ref>{{harvnb|CRC|2006|pp='''12'''–11–12}}</ref> and in other circumstances where ionic radius is a determining factor, the chemistry of zinc has much in common with that of magnesium.<ref name="Holl">{{Cite book|publisher=Walter de Gruyter|date=1985|edition=91–100| pages=1034–1041|isbn=978-3-11-007511-3|title=Lehrbuch der Anorganischen Chemie|first1=Arnold F.|last1=Holleman|last2=Wiberg|first2=Egon|last3=Wiberg|first3=Nils|language=de|chapter=Zink}}</ref> In other respects, there is little similarity with the late first-row transition metals. Zinc tends to form bonds with a greater degree of [[covalency]] and much more stable [[Complex (chemistry)|complexes]] with [[nitrogen|N]]- and [[sulfur|S]]- donors.<ref name="Greenwood1997p1206">{{harvnb|Greenwood|Earnshaw|1997|p=1206}}</ref> Complexes of zinc are mostly 4- or 6- [[coordinate covalent bond|coordinate]], although 5-coordinate complexes are known.<ref name="Holl" />
===Zinc(I) compounds===
Zinc(I) compounds are very rare. The [Zn<sub>2</sub>]<sup>2+</sup> ion is implicated by the formation of a yellow diamagnetic glass by dissolving metallic zinc in molten ZnCl<sub>2</sub>.<ref>{{Housecroft3rd|page=739–741, 843}}</ref> The [Zn<sub>2</sub>]<sup>2+</sup> core would be analogous to the [Hg<sub>2</sub>]<sup>2+</sup> cation present in [[mercury (element)|mercury]](I) compounds. The [[diamagnetism|diamagnetic]] nature of the ion confirms its dimeric structure. The first zinc(I) compound containing the Zn–Zn bond, [[Decamethyldizincocene|(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>Zn<sub>2</sub>]].
===Zinc(II) compounds===
[[File:Zinc acetate.JPG|thumb|left|[[Zinc acetate]], {{chem|Zn|(|C|H|3|C|O|2|)|2}}|alt=Sheets of zinc acetate formed by slow evaporation]]
[[File:Zinc chloride.jpg|thumb|Zinc chloride|alt=White lumped powder on a glass plate]]
[[Binary compound]]s of zinc are known for most of the [[metalloid]]s and all the [[Nonmetal (chemistry)|nonmetal]]s except the [[noble gas]]es. The oxide [[zinc oxide|ZnO]] is a white powder that is nearly insoluble in neutral aqueous solutions, but is [[amphoteric]], dissolving in both strong basic and acidic solutions.<ref name="Holl" /> The other [[chalcogen]]ides ([[zinc sulfide|ZnS]], [[zinc selenide|ZnSe]], and [[zinc telluride|ZnTe]]) have varied applications in electronics and optics.<ref>{{cite web|url=http://www.americanelements.com/znsu.html|title=Zinc Sulfide|publisher=[[American Elements]]|access-date=February 3, 2009|url-status=live|archive-url=https://archive.today/20120717190353/http://www.americanelements.com/znsu.html|archive-date=July 17, 2012}}</ref> [[Pnictogenide]]s ([[Zinc nitride|{{chem|Zn|3|N|2}}]], [[zinc phosphide|{{chem|Zn|3|P|2}}]], [[zinc arsenide|{{chem|Zn|3|As|2}}]] and [[zinc antimonide|{{chem|Zn|3|Sb|2}}]]),<ref>{{cite book|title=Academic American Encyclopedia|url=https://books.google.com/books?id=YgI4E7w5JI8C|date=1994|publisher=Grolier Inc.| location=[[Danbury, Connecticut]] |isbn=978-0-7172-2053-3|page=202}}</ref><ref>{{cite web|url=http://www.americanelements.com/znp.html|title=Zinc Phosphide|publisher=[[American Elements]]|access-date=February 3, 2009|url-status=live|archive-url=https://archive.today/20120717120313/http://www.americanelements.com/znp.html|archive-date=July 17, 2012}}</ref> the peroxide ([[zinc peroxide|{{chem|ZnO|2}}]]), the hydride ([[zinc hydride|{{chem|ZnH|2}}]]), and the carbide ({{chem|ZnC|2}}) are also known.<ref>{{Cite journal|journal=Diamond and Related Materials|volume=9|date=2000|title=Peculiarities of interaction in the Zn–C system under high pressures and temperatures |issue=2|vauthors=Shulzhenko AA, Ignatyeva IY, Osipov AS, Smirnova TI |doi=10.1016/S0925-9635(99)00231-9|pages=129–133|bibcode = 2000DRM.....9..129S }}</ref> Of the four [[halide]]s, [[zinc fluoride|{{chem|ZnF|2}}]] has the most ionic character, while the others ([[zinc chloride|{{chem|ZnCl|2}}]], [[zinc bromide|{{chem|ZnBr|2}}]], and [[zinc iodide|{{chem|ZnI|2}}]]) have relatively low melting points and are considered to have more covalent character.<ref name="Greenwood1997p1211">{{harvnb|Greenwood|Earnshaw|1997|p=1211}}</ref>
In weak basic solutions containing {{chem|Zn|2+}} ions, the hydroxide [[Zinc hydroxide|{{chem|Zn(OH)|2}}]] forms as a white [[precipitate]]. In stronger alkaline solutions, this hydroxide is dissolved to form zincates ([[zincate|{{chem|[Zn||(OH)<sub>4</sub>]|2-}}]]).<ref name="Holl" /> The nitrate [[Zinc nitrate|{{chem|Zn(NO<sub>3</sub>)|2}}]], chlorate [[Zinc chlorate|{{chem|Zn(ClO<sub>3</sub>)|2}}]], sulfate [[Zinc sulfate|{{chem|ZnSO|4}}]], phosphate [[Zinc phosphate|{{chem|Zn|3|(PO<sub>4</sub>)|2}}]], molybdate [[Zinc molybdate|{{chem|ZnMoO|4}}]], cyanide [[Zinc cyanide|{{chem|Zn(CN)|2}}]], arsenite {{chem|Zn(AsO<sub>2</sub>)|2}}, arsenate {{chem|Zn(AsO<sub>4</sub>)|2|·8H|2|O}} and the chromate [[Zinc chromate|{{chem|ZnCrO|4}}]] (one of the few colored zinc compounds) are a few examples of other common inorganic compounds of zinc.<ref>{{Cite journal| last=Rasmussen| first=J. K.| author2=Heilmann, S. M.| title=In situ Cyanosilylation of Carbonyl Compounds: O-Trimethylsilyl-4-Methoxymandelonitrile| journal=Organic Syntheses, Collected Volume| volume=7| page=521| date=1990| url=http://www.orgsyn.org/orgsyn/prep.asp?prep=cv7p0521| url-status=live| archive-url=https://web.archive.org/web/20070930230236/http://www.orgsyn.org/orgsyn/prep.asp?prep=cv7p0521| archive-date=September 30, 2007| df=mdy-all}}</ref><ref name="perry">{{Cite book|title=Handbook of Inorganic Compounds|last=Perry|first=D. L.|pages=448–458|date=1995|isbn=978-0-8493-8671-8|publisher=CRC Press}}</ref>
[[Organozinc compound]]s are those that contain zinc–[[carbon]] covalent bonds. Diethylzinc ([[Diethylzinc|{{chem|(C|2|H<sub>5</sub>)|2|Zn}}]]) is a reagent in synthetic chemistry. It was first reported in 1848 from the reaction of zinc and [[ethyl iodide]], and was the first compound known to contain a metal–carbon [[sigma bond]].<ref>{{Cite journal|title=On the isolation of the organic radicals|author=Frankland, E.|journal=Quarterly Journal of the Chemical Society|date=1850|volume=2|issue=3|page=263|doi=10.1039/QJ8500200263|url=https://zenodo.org/record/1861200|author-link=Edward Frankland}}</ref>
===Test for zinc===
Cobalticyanide paper (Rinnmann's test for Zn) can be used as a chemical indicator for zinc. 4&nbsp;g of K<sub>3</sub>Co(CN)<sub>6</sub> and 1&nbsp;g of KClO<sub>3</sub> is dissolved on 100&nbsp;ml of water. Paper is dipped in the solution and dried at 100&nbsp;°C. One drop of the sample is dropped onto the dry paper and heated. A green disc indicates the presence of zinc.<ref>{{Cite book|title=CRC- Handbook of Chemistry and Physics|last=Lide|first=David|publisher=CRC press|year=1998|isbn=978-0-8493-0479-8|pages=Section 8 Page 1}}</ref>
{{clear}}
==History==
===Ancient use===
Various isolated examples of the use of impure zinc in ancient times have been discovered. Zinc ores were used to make the zinc–copper alloy [[brass]] thousands of years prior to the discovery of zinc as a separate element. Judean brass from the 14th to 10th centuries&nbsp;BC contains 23% zinc.<ref name="Greenwood1997p1201">{{harvnb|Greenwood|Earnshaw|1997|p=1201}}</ref>
Knowledge of how to produce brass spread to [[Ancient Greece]] by the 7th&nbsp;century&nbsp;BC, but few varieties were made.<ref name="jas5">{{cite journal|last=Craddock|first=Paul T.|date=1978|title=The composition of copper alloys used by the Greek, Etruscan and Roman civilizations. The origins and early use of brass|journal=Journal of Archaeological Science|volume=5|issue=1|pages=1–16|doi=10.1016/0305-4403(78)90015-8}}</ref> Ornaments made of [[alloy]]s containing 80–90% zinc, with lead, iron, [[antimony]], and other metals making up the remainder, have been found that are 2,500 years old.<ref name="Lehto1968p822">{{harvnb|Lehto|1968|p=822}}</ref> A possibly prehistoric statuette containing 87.5% zinc was found in a [[Dacia]]n archaeological site.<ref name="Weeks1933p20">{{harvnb|Weeks|1933|p=20}}</ref>
[[Strabo]] writing in the 1st century BC (but quoting a now lost work of the 4th century BC historian [[Theopompus]]) mentions "drops of false silver" which when mixed with copper make brass. This may refer to small quantities of zinc that is a by-product of smelting [[sulfide]] ores.<ref>{{Cite book |author=Craddock, P. T. |chapter=Zinc in classical antiquity |editor=Craddock, P.T. |title=2000 years of zinc and brass |publisher=British Museum |location=London |date=1998 |isbn=978-0-86159-124-4 |pages=3–5 |edition=rev.}}</ref> Zinc in such remnants in smelting ovens was usually discarded as it was thought to be worthless.<ref name="Weeks1933p21">{{harvnb|Weeks|1933|p=21}}</ref>
The manufacture of brass was known to the [[Ancient Rome|Romans]] by about 30&nbsp;BC.<ref name="Emsley2001p501" /> They made brass by heating powdered [[Calamine (mineral)|calamine]] (zinc [[silicate]] or carbonate), charcoal and copper together in a crucible.<ref name="Emsley2001p501">{{harvnb|Emsley|2001|p=501}}</ref> The resulting [[calamine brass]] was then either cast or hammered into shape for use in weaponry.<ref>{{cite web|title=How is zinc made? |work=How Products are Made |date=2002 |publisher=The Gale Group |url=http://www.answers.com/zinc |access-date=February 21, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20060411200556/http://www.answers.com/zinc |archive-date=April 11, 2006 }}</ref> Some coins struck by Romans in the Christian era are made of what is probably calamine brass.<ref name="Chambers1901p799">{{harvnb|Chambers|1901|p=799}}</ref>
[[File:Hemmoorer Eimer.jpg|upright|thumb|Late Roman brass bucket – the [[Hemmoor]]er Eimer from Warstade, Germany, second to third century AD|alt=Large black bowl-shaped bucket on a stand. The bucket has incrustation around its top.]]
The oldest known pills were made of the zinc carbonates hydrozincite and smithsonite. The pills were used for sore eyes and were found aboard the Roman ship [[Relitto del Pozzino]], wrecked in 140 BC.<ref>{{cite web |url=https://www.newscientist.com/article/dn23049-worlds-oldest-pills-treated-sore-eyes.html |title=World's oldest pills treated sore eyes |work=New Scientist |date=January 7, 2013 |access-date=February 5, 2013 |url-status=live |archive-url=https://web.archive.org/web/20130122102750/http://www.newscientist.com/article/dn23049-worlds-oldest-pills-treated-sore-eyes.html |archive-date=January 22, 2013 }}</ref><ref>{{cite journal|doi= 10.1073/pnas.1216776110|pmid=23297212|pmc=3557061|title=Ingredients of a 2,000-y-old medicine revealed by chemical, mineralogical, and botanical investigations|journal=Proceedings of the National Academy of Sciences|volume=110|issue=4|pages=1193–1196|bibcode=2013PNAS..110.1193G|year=2013|last1=Giachi|first1=Gianna|last2=Pallecchi|first2=Pasquino|last3=Romualdi|first3=Antonella|last4=Ribechini|first4=Erika|last5=Lucejko|first5=Jeannette Jacqueline|last6=Colombini|first6=Maria Perla|last7=Mariotti Lippi|first7=Marta|doi-access=free}}</ref>
The [[Berne zinc tablet]] is a votive plaque dating to [[Roman Gaul]] made of an alloy that is mostly zinc.<ref>{{Cite book|last=Rehren|first=Th.|date=1996|title=A Roman zinc tablet from Bern, Switzerland: Reconstruction of the Manufacture|publisher=Archaeometry 94. The Proceedings of the 29th International Symposium on Archaeometry|editor=S. Demirci|display-editors=etal|pages=35–45}}</ref>
The [[Charaka Samhita]], thought to have been written between 300 and 500 AD,<ref>{{cite book|author=Meulenbeld, G. J.|title=A History of Indian Medical Literature|publisher=Forsten|location=Groningen|date=1999|oclc=165833440|volume=IA|pages=130–141}}</ref> mentions a metal which, when oxidized, produces ''pushpanjan'', thought to be zinc oxide.<ref>{{Cite book |author=Craddock, P. T. |display-authors=etal|chapter=Zinc in India |title=2000 years of zinc and brass |publisher=British Museum |location=London |date=1998 |isbn=978-0-86159-124-4 |page=27 |edition=rev.}}</ref> Zinc mines at Zawar, near [[Udaipur]] in India, have been active since the [[Mauryan period]] ({{circa| 322}} and 187 BCE). The smelting of metallic zinc here, however, appears to have begun around the 12th century AD.<ref name="ammraja">p. 46, Ancient mining and metallurgy in Rajasthan, S. M. Gandhi, chapter 2 in ''Crustal Evolution and Metallogeny in the Northwestern Indian Shield: A Festschrift for Asoke Mookherjee'', M. Deb, ed., Alpha Science Int'l Ltd., 2000, {{ISBN|1-84265-001-7}}.</ref><ref name="Craddock">{{Cite journal|last=Craddock|first=P. T.|author2=Gurjar L. K. |author3=Hegde K. T. M. |title=Zinc production in medieval India|journal=World Archaeology|volume=15|issue=2|date=1983|jstor=124653
|pages=211–217|doi=10.1080/00438243.1983.9979899}}</ref> One estimate is that this location produced an estimated million tonnes of metallic zinc and zinc oxide from the 12th to 16th centuries.<ref name="Emsley2001p502">{{harvnb|Emsley|2001|p=502}}</ref> Another estimate gives a total production of 60,000 tonnes of metallic zinc over this period.<ref name="ammraja" /> The [[Rasaratna Samuccaya]], written in approximately the 13th century AD, mentions two types of zinc-containing ores: one used for metal extraction and another used for medicinal purposes.<ref name="Craddock" />
===Early studies and naming===
Zinc was distinctly recognized as a metal under the designation of ''Yasada'' or Jasada in the medical Lexicon ascribed to the Hindu king Madanapala (of Taka dynasty) and written about the year 1374.<ref name="Ray1903">{{cite book|last=Ray|first=Prafulla Chandra|title=A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century, A.D.: With Sanskrit Texts, Variants, Translation and Illustrations|publisher=The Bengal Chemical & Pharmaceutical Works, Ltd|date=1903|edition=2nd|volume=1|pages=157–158|url=https://books.google.com/books?id=DL1HAAAAIAAJ}} (public domain text)</ref> Smelting and extraction of impure zinc by reducing calamine with wool and other organic substances was accomplished in the 13th century in India.<ref name="CRCp4-41">{{harvnb|CRC|2006|p='''4'''–41}}<!-- sic "-" not a range! --></ref><ref name="iza">{{cite web|last=Habashi|first=Fathi|title=Discovering the 8th Metal|publisher=International Zinc Association (IZA)|url=http://www.iza.com/Documents/Communications/Publications/History.pdf|archive-url=https://web.archive.org/web/20090304154217/http://www.iza.com/Documents/Communications/Publications/History.pdf|archive-date=March 4, 2009|access-date=December 13, 2008}}</ref> The Chinese did not learn of the technique until the 17th century.<ref name="iza" />
[[File:Zinc symbol (fixed width).svg|thumb|left|[[Alchemical symbol]] for the element zinc]]
[[Alchemy|Alchemists]] burned zinc metal in air and collected the resulting zinc oxide on a [[Condenser (heat transfer)|condenser]]. Some alchemists called this zinc oxide ''lana philosophica'', Latin for "philosopher's wool", because it collected in wooly tufts, whereas others thought it looked like white snow and named it ''nix album''.<ref>{{Cite book|last=Arny|first=Henry Vinecome|url=https://books.google.com/books?id=gRNKAAAAMAAJ|title=Principles of Pharmacy|publisher=W. B. Saunders company|date=1917|edition=2nd|page=483}}</ref>
The name of the metal was probably first documented by [[Paracelsus]], a Swiss-born German alchemist, who referred to the metal as "zincum" or "zinken" in his book ''Liber Mineralium II'', in the 16th century.<ref name="iza" /><ref>{{Cite book|title=Georgius Agricola de Re Metallica|first=Herbert Clark|last=Hoover|publisher=Kessinger Publishing|date=2003|page=409|isbn=978-0-7661-3197-2}}</ref> The word is probably derived from the German {{lang|de|zinke}}, and supposedly meant "tooth-like, pointed or jagged" (metallic zinc crystals have a needle-like appearance).<ref>{{Cite book|title=Ullmann's Encyclopedia of Industrial Chemistry|last=Gerhartz|display-authors=etal |edition=5th|date=1996|isbn=978-3-527-20100-6|publisher=VHC|page=509|first=Wolfgang}}</ref> ''Zink'' could also imply "tin-like" because of its relation to German ''zinn'' meaning tin.<ref>{{Cite book|author=Skeat, W. W|title=Concise Etymological Dictionary of the English Language|url=https://books.google.com/books?id=ls_XijT33IUC&pg=PA622|page=622|publisher=Cosimo, Inc.|date=2005|isbn=978-1-59605-092-1}}</ref> Yet another possibility is that the word is derived from the [[Persian language|Persian]] word {{lang|fa|سنگ}} ''seng'' meaning stone.<ref>{{Cite book|title=Handbook of Extractive Metallurgy|author=Fathi Habashi|date=1997|isbn=978-3-527-28792-5|publisher=Wiley-VHC|page=642}}</ref> The metal was also called ''Indian tin'', ''tutanego'', ''calamine'', and ''spinter''.<ref name="Lehto1968p822" />
German metallurgist [[Andreas Libavius]] received a quantity of what he called "calay" (from the Malay or Hindi word for tin) originating from [[Malabar Coast|Malabar]] off a cargo ship captured from the Portuguese in the year 1596.<ref>{{Cite book|last=Lach|first=Donald F.|title=Asia in the Making of Europe|chapter=Technology and the Natural Sciences|page=426|chapter-url=https://books.google.com/books?id=N0xD7BYXv_YC&pg=PA426|date=1994|isbn=978-0-226-46734-4|publisher=[[University of Chicago Press]]}}</ref> Libavius described the properties of the sample, which may have been zinc. Zinc was regularly imported to Europe from the Orient in the 17th and early 18th centuries,<ref name="iza" /> but was at times very expensive.{{efn|An [[East India Company]] ship carrying a cargo of nearly pure zinc metal from the Orient sank off the coast [[Sweden]] in 1745.{{harv|Emsley|2001|p=502}}}}
===Isolation===
[[File:Andreas Sigismund Marggraf-flip.jpg|thumb|upright|[[Andreas Sigismund Marggraf]] is given credit for first isolating pure zinc|alt=Picture of an old man head (profile). The man has a long face, short hair and tall forehead.]]
Metallic zinc was isolated in India by 1300 AD.<ref>{{cite book|last=Vaughan|first=L Brent |date=1897 |title=The Junior Encyclopedia Britannica A Reference Library of General Knowledge Volume III P-Z|location=Chicago |publisher=E. G. Melven & Company|article=Zincography}}</ref><ref>{{cite web|url=http://science.marshall.edu/castella/chm448/elements3.pdf|title=Transition Metal Elements|author=Castellani, Michael|access-date=October 14, 2014|url-status=live|archive-url=https://web.archive.org/web/20141010201408/http://science.marshall.edu/castella/chm448/elements3.pdf|archive-date=October 10, 2014}}</ref><ref>{{cite book |last1=Habib |first1=Irfan |editor-last=Chatopadhyaya |editor-first=D. P. |date=2011 |title=Economic History of Medieval India, 1200–1500 |url=https://books.google.com/books?id=K8kO4J3mXUAC&pg=PA86 |location=New Delhi |publisher=Pearson Longman |page=86 |isbn=978-81-317-2791-1 |url-status=live |archive-url=https://web.archive.org/web/20160414222551/https://books.google.com/books?id=K8kO4J3mXUAC&pg=PA86 |archive-date=April 14, 2016 }}</ref> Before it was isolated in Europe, it was imported from India in about 1600 CE.<ref name="zinc-eng" /> [[Postlewayt]]'s ''Universal Dictionary'', a contemporary source giving technological information in Europe, did not mention zinc before 1751 but the element was studied before then.<ref name="Craddock" /><ref>{{Cite journal|title=Ancient Lead and Zinc Mining in Rajasthan, India|author1=Willies, Lynn|author2=Craddock, P. T.|author3=Gurjar, L. J.|author4=Hegde, K. T. M. |volume=16|issue=2, Mines and Quarries|date=1984|journal=World Archaeology|jstor=124574|pages=222–233|doi=10.1080/00438243.1984.9979929}}</ref>
Flemish [[metallurgist]] and [[alchemist]] [[P. M. de Respour]] reported that he had extracted metallic zinc from zinc oxide in 1668.<ref name="Emsley2001p502" /> By the start of the 18th century, [[Étienne François Geoffroy]] described how zinc oxide condenses as yellow crystals on bars of iron placed above zinc ore that is being smelted.<ref name="Emsley2001p502" /> In Britain, [[John Lane (metallurgist)|John Lane]] is said to have carried out experiments to smelt zinc, probably at [[Landore]], prior to his bankruptcy in 1726.<ref>{{Cite journal|last=Roberts|first=R. O.|date=1951|title=Dr John Lane and the foundation of the non-ferrous metal industry in the Swansea valley|journal=Gower|publisher=Gower Society|issue=4|page=19}}</ref>
In 1738 in Great Britain, [[William Champion (metallurgist)|William Champion]] patented a process to extract zinc from calamine in a vertical [[retort]]-style smelter.<ref>{{Cite book|last=Comyns|first=Alan E.|title=Encyclopedic Dictionary of Named Processes in Chemical Technology|edition=3rd|publisher=CRC Press|isbn=978-0-8493-9163-7|date=2007|page=71|url=https://books.google.com/books?id=Jlq-ckWvQSQC}}</ref> His technique resembled that used at Zawar zinc mines in [[Rajasthan]], but no evidence suggests he visited the Orient.<ref name="zinc-eng">{{Cite journal|first=Rhys|last=Jenkins|title=The Zinc Industry in England: the early years up to 1850|journal=Transactions of the Newcomen Society|volume=25|date=1945|pages=41–52|doi=10.1179/tns.1945.006}}</ref> Champion's process was used through 1851.<ref name="iza" />
German chemist [[Andreas Sigismund Marggraf|Andreas Marggraf]] normally gets credit for isolating pure metallic zinc in the West, even though Swedish chemist Anton von Swab had distilled zinc from calamine four years previously.<ref name="iza" /> In his 1746 experiment, Marggraf heated a mixture of calamine and charcoal in a closed vessel without copper to obtain a metal.<ref>{{cite journal |last1=Marggraf |title=Experiences sur la maniere de tirer le Zinc de sa veritable miniere, c'est à dire, de la pierre calaminaire |journal=Histoire de l'Académie Royale des Sciences et Belles-Lettres de Berlin |date=1746 |volume=2 |pages=49–57 |url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015026296437&view=1up&seq=93 |trans-title=Experiments on a way of extracting zinc from its true mineral; i.e., the stone calamine |language=fr}}</ref><ref name="Weeks1933p21" /> This procedure became commercially practical by 1752.<ref>{{harvnb|Heiserman|1992|p=122}}</ref>
===Later work===
[[File:Luigi Galvani, oil-painting.jpg|thumb|upright|left|[[Galvanization]] was named after [[Luigi Galvani]].|alt=Painting of a middle-aged man sitting by the table, wearing a wig, black jacket, white shirt and white scarf.]]
William Champion's brother, John, patented a process in 1758 for [[calcining]] zinc sulfide into an oxide usable in the retort process.<ref name="Lehto1968p822" /> Prior to this, only calamine could be used to produce zinc. In 1798, [[Johann Christian Ruberg]] improved on the smelting process by building the first horizontal retort smelter.<ref>{{Cite book|last=Gray|title=Zinc|date=2005|isbn=978-0-7614-1922-8|publisher=Marshall Cavendish|page=[https://archive.org/details/zinc0000gray/page/8 8]|first=Leon|url=https://archive.org/details/zinc0000gray/page/8}}</ref> [[Jean-Jacques Daniel Dony]] built a different kind of horizontal zinc smelter in Belgium that processed even more zinc.<ref name="iza" />
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The Zinc Industry
Von Ernest Alfred Smith
Veröffentlicht von BiblioBazaar, LLC, 2008
ISBN 0-554-78657-5, ISBN 978-0-554-78657-5
https://books.google.com/books?id=wgkHP35JP1gC
<ref>{{Cite book|title=An Encyclopaedia of the History of Technology|chapter=Zinc|first=Ian|last=McNeil|publisher=Taylor & Francis|year=1990|isbn=978-0-415-01306-2|pages=73–96}}</ref>
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Italian doctor [[Luigi Galvani]] discovered in 1780 that connecting the [[spinal cord]] of a freshly dissected frog to an iron rail attached by a brass hook caused the frog's leg to twitch.<ref name="ExcelPhysics">{{Cite book|title=Excel Preliminary Physics|last=Warren|first=Neville G.|publisher=Pascal Press|date=2000|page=47|isbn=978-1-74020-085-1|url=https://books.google.com/books?id=eL9Xn6nQ6XQC}}</ref> He incorrectly thought he had discovered an ability of nerves and muscles to create [[electricity]] and called the effect "[[bioelectricity|animal electricity]]".<ref name="IntEncyl">{{Cite book|title=The New International Encyclopaedia|chapter=Galvanic Cell|page=80|date=1903|publisher=Dodd, Mead and Company|chapter-url=https://books.google.com/books?id=gV1MAAAAMAAJ&pg=PA80}}</ref> The galvanic cell and the process of galvanization were both named for Luigi Galvani, and his discoveries paved the way for [[Battery (electricity)|electrical batteries]], galvanization, and [[cathodic protection]].<ref name="IntEncyl" />
Galvani's friend, [[Alessandro Volta]], continued researching the effect and invented the [[Voltaic pile]] in 1800.<ref name="ExcelPhysics" /> Volta's pile consisted of a stack of simplified [[galvanic cell]]s, each being one plate of copper and one of zinc connected by an [[electrolyte]]. By stacking these units in series, the Voltaic pile (or "battery") as a whole had a higher voltage, which could be used more easily than single cells. Electricity is produced because the [[Volta potential]] between the two metal plates makes [[electron]]s flow from the zinc to the copper and corrode the zinc.<ref name="ExcelPhysics" />
The non-magnetic character of zinc and its lack of color in solution delayed discovery of its importance to biochemistry and nutrition.<ref name="Cotton1999p626" /> This changed in 1940 when [[carbonic anhydrase]], an enzyme that scrubs carbon dioxide from blood, was shown to have zinc in its [[active site]].<ref name="Cotton1999p626" /> The digestive enzyme [[carboxypeptidase]] became the second known zinc-containing enzyme in 1955.<ref name="Cotton1999p626">{{harvnb|Cotton et al.|1999|p=626}}</ref>
{{clear}}
==Production==
===Mining and processing===
{| class="wikitable" style="float:right; margin-left:0.5em"
|+ Top zinc mine production output (by countries) 2023<ref>[https://pubs.usgs.gov/periodicals/mcs2024/mcs2024-zinc.pdf Mineral Commodity Summaries 2024]</ref>
|- class="hintergrundfarbe6"
! [[Ranking|Rank]] !![[Country]] !![[Tonne]]s
|-
| '''1'''||'''[[China]]''' ||align="right"| '''4,000,000'''
|-
| '''2'''||'''[[Peru]]''' ||align="right"| '''1,400,000'''
|-
| '''3'''||'''[[Australia]]''' ||align="right"| '''1,100,000'''
|-
| '''4'''||'''[[India]]'''|| align="right" | '''860,000'''
|-
| '''5'''||'''[[United States]]'''|| align="right" | '''750,000'''
|-
| '''6'''||'''[[Mexico]]''' ||align="right"| '''690,000'''
|}
{{Main|Zinc mining|Zinc smelting}}
{{See also|List of countries by zinc production}}
[[File:Price of Zinc.webp|thumb|325px|right|Price of Zinc]]
[[File:World Zinc Production 2006.svg|thumb|upright=1.6|Percentage of zinc output in 2006 by countries<ref name="USGSCS2008">{{cite web|url=http://minerals.er.usgs.gov/minerals/pubs/commodity/zinc/mcs-2008-zinc.pdf|first=Stephen M.|last=Jasinski|publisher=United States Geological Survey|access-date=November 25, 2008|title=Mineral Commodity Summaries 2007: Zinc|url-status=live|archive-url=https://web.archive.org/web/20081217021239/http://minerals.er.usgs.gov/minerals/pubs/commodity/zinc/mcs-2008-zinc.pdf|archive-date=December 17, 2008}}</ref>|alt=World map revealing that about 40% of zinc is produced in China, 20% in Australia, 20% in Peru, and 5% in US, Canada and Kazakhstan each.]]
[[File:Zinc world production.svg|thumb|lang=en|World production trend]]
[[File:Zink Mine Rosh Pinah.jpg|thumb|Zinc Mine Rosh Pinah, [[Namibia]]<br />{{coord|27|57|17|S|016|46|00|E|region:NA_type:landmark|name=Rosh Pinah}}]]
[[File:Skorpion Zink Mine.jpg|thumb|Zinc Mine Skorpion, [[Namibia]]<br />{{coord|27|49|09|S|016|36|28|E|region:NA_type:landmark|name=Skorpion}}]]
Zinc is the fourth most common metal in use, trailing only [[iron]], [[aluminium]], and [[copper]] with an annual production of about 13 million tonnes.<ref name="USGSMCS2015" /> The world's largest zinc producer is [[Nyrstar]], a merger of the Australian [[OZ Minerals]] and the Belgian [[Umicore]].<ref>{{cite web|url=https://www.wsj.com/articles/SB116590371844647445|title=Zinifex, Umicore Combine to Form Top Zinc Maker|last=Attwood|first=James|work=[[The Wall Street Journal]]|date=February 13, 2006|url-status=live|archive-url=https://web.archive.org/web/20170126122526/http://www.wsj.com/articles/SB116590371844647445|archive-date=January 26, 2017}}</ref> About 70% of the world's zinc originates from mining, while the remaining 30% comes from recycling secondary zinc.<ref>{{cite web|url=http://www.zincworld.org/recycling.html |title=Zinc Recycling |publisher=International Zinc Association |access-date=November 28, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20111021135539/http://www.zincworld.org/recycling.html |archive-date=October 21, 2011 }}</ref>
{{anchor|Commercially pure zinc}}
Commercially pure zinc is known as Special High Grade, often abbreviated ''SHG'', and is 99.995% pure.<ref>{{cite web|title=Special High Grade Zinc (SHG) 99.995%|url=http://nyrstar.com/nyrstar/en/products/zinccongalvanising/techdownloads/shg_budel.pdf|archive-url=https://web.archive.org/web/20090304154218/http://nyrstar.com/nyrstar/en/products/zinccongalvanising/techdownloads/shg_budel.pdf|archive-date=March 4, 2009| access-date=December 1, 2008|date=2008|publisher=Nyrstar}}</ref>
Worldwide, 95% of new zinc is mined from [[sulfide|sulfidic]] ore deposits, in which sphalerite (ZnS) is nearly always mixed with the sulfides of copper, lead and iron.<ref name="Zinchand" />{{Rp|page=6}} Zinc mines are scattered throughout the world, with the main areas being China, Australia, and Peru. China produced 38% of the global zinc output in 2014.<ref name="USGSMCS2015" />
Zinc metal is produced using [[extractive metallurgy]].<ref name="Rosenqvist1922">{{Cite book|title=Principles of Extractive Metallurgy|last=Rosenqvist|first=Terkel|pages=7, 16, 186|edition=2nd|date=1922|isbn=978-82-519-1922-7|publisher=Tapir Academic Press}}</ref>{{Rp|page=7}} The ore is finely ground, then put through [[froth flotation]] to separate minerals from [[gangue]] (on the property of [[hydrophobicity]]), to get a zinc sulfide ore concentrate<ref name="Rosenqvist1922" />{{Rp|page=16}} consisting of about 50% zinc, 32% sulfur, 13% iron, and 5% {{chem|SiO|2}}.<ref name="Rosenqvist1922" />{{Rp|page=16}}
[[Roasting (metallurgy)|Roasting]] converts the zinc sulfide concentrate to zinc oxide:<ref name="Zinchand">{{Cite book|url=https://books.google.com/books?id=laACw9i0D_wC|title=Zinc Handbook|first=Frank C.|last=Porter|publisher=CRC Press|date=1991|isbn=978-0-8247-8340-2}}</ref>
:<chem>2ZnS + 3O2  ->[t^o] 2ZnO + 2SO2</chem>
The [[sulfur dioxide]] is used for the production of sulfuric acid, which is necessary for the leaching process. If deposits of [[zinc carbonate]], [[zinc silicate]], or [[zinc-spinel]] (like the [[Skorpion Zinc|Skorpion Deposit]] in [[Namibia]]) are used for zinc production, the roasting can be omitted.<ref name="Skorpion">{{Cite journal|journal=Economic Geology|date=2003|volume=98|issue=4|pages=749–771|doi=10.2113/98.4.749|title=Geology of the Skorpion Supergene Zinc Deposit, Southern Namibia|first=Gregor|last=Borg|author2=Kärner, Katrin |author3=Buxton, Mike |author4=Armstrong, Richard |author5= van der Merwe, Schalk W. }}</ref>
For further processing two basic methods are used: [[pyrometallurgy]] or [[electrowinning]]. Pyrometallurgy reduces zinc oxide with [[carbon]] or [[carbon monoxide]] at {{convert|950|C|F|abbr=on}} into the metal, which is distilled as zinc vapor to separate it from other metals, which are not volatile at those temperatures.<ref>{{Cite book|last=Bodsworth|first=Colin|title=The Extraction and Refining of Metals|page=148|date=1994|isbn=978-0-8493-4433-6|publisher=CRC Press}}</ref> The zinc vapor is collected in a condenser.<ref name="Zinchand" /> The equations below describe this process:<ref name="Zinchand" />
: <chem>ZnO + C ->[950^oC] Zn + CO</chem>
: <chem>ZnO + CO ->[950^oC] Zn + CO2</chem>
In [[electrowinning]], zinc is leached from the ore concentrate by [[sulfuric acid]] and impurities are precipitated:<ref>{{Cite book|title=Hydrometallurgy in Extraction Processes|last=Gupta|first=C. K.|author2=Mukherjee, T. K. |page=62|publisher=CRC Press|isbn=978-0-8493-6804-2|date=1990}}</ref>
:<chem>ZnO + H2SO4 -> ZnSO4 + H2O</chem>
Finally, the zinc is reduced by [[electrolysis]].<ref name="Zinchand" />
:<chem>2ZnSO4 + 2H2O -> 2Zn + O2 + 2H2SO4</chem>
The sulfuric acid is regenerated and recycled to the leaching step.
When galvanised feedstock is fed to an [[electric arc furnace]], the zinc is recovered from the dust by a number of processes, predominantly the [[Waelz process]] (90% as of 2014).<ref>{{citation| title = Handbook of Recycling: State-of-the-art for Practitioners, Analysts, and Scientists| editor-first = Ernst| editor-last = Worrell| editor-first2= Markus|editor-last2= Reuter| date = 2014| chapter =9. Zinc and Residue Recycling| first1 = Jürgen| last1 = Antrekowitsch| first2= Stefan| last2= Steinlechner| first3 = Alois| last3= Unger| first4 = Gernot| last4 = Rösler| first5 = Christoph| last5 = Pichler| first6 = Rene| last6 = Rumpold}}</ref>
===Environmental impact===
Refinement of sulfidic zinc ores produces large volumes of sulfur dioxide and [[cadmium]] vapor. Smelter [[slag]] and other residues contain significant quantities of metals. About 1.1&nbsp;million tonnes of metallic zinc and 130 thousand tonnes of lead were mined and smelted in the Belgian towns of [[Kelmis|La Calamine]] and [[Plombières]] between 1806 and 1882.<ref name="Kucha">{{Cite journal|journal=Environmental Geology|date=1996|volume=27|first=H.|last=Kucha|issue=1|author2=Martens, A.|author3=Ottenburgs, R.|author4=De Vos, W.|author5=Viaene, W.|title=Primary minerals of Zn-Pb mining and metallurgical dumps and their environmental behavior at Plombières, Belgium|doi=10.1007/BF00770598|pages=1–15|bibcode=1996EnGeo..27....1K|s2cid=129717791}}</ref> The dumps of the past mining operations leach zinc and cadmium, and the sediments of the [[Geul River]] contain non-trivial amounts of metals.<ref name="Kucha" /> About two thousand years ago, emissions of zinc from mining and smelting totaled 10 thousand tonnes a year. After increasing 10-fold from 1850, zinc emissions peaked at 3.4&nbsp;million tonnes per year in the 1980s and declined to 2.7&nbsp;million tonnes in the 1990s, although a 2005 study of the Arctic troposphere found that the concentrations there did not reflect the decline. Man-made and natural emissions occur at a ratio of 20&nbsp;to&nbsp;1.<ref name="Broadley2007" />
Zinc in rivers flowing through industrial and mining areas can be as high as 20&nbsp;ppm.<ref name="Emsley2001p504">{{harvnb|Emsley|2001|p=504}}</ref> Effective [[sewage treatment]] greatly reduces this; treatment along the [[Rhine]], for example, has decreased zinc levels to 50&nbsp;ppb.<ref name="Emsley2001p504" /> Concentrations of zinc as low as 2&nbsp;ppm adversely affects the amount of oxygen that fish can carry in their blood.<ref>{{Cite book|last=Heath|first=Alan G.|title=Water pollution and fish physiology|publisher=CRC Press|location=Boca Raton, Florida|date=1995|page=57|isbn=978-0-87371-632-1|url=https://books.google.com/books?id=5NPVTuBtGF4C}}</ref>
{{wide image|The Zinc Works and Incat.jpg|1150px|Historically responsible for high metal levels in the [[Derwent River (Tasmania)|Derwent River]],<ref>{{cite web|url=http://www.derwentestuary.org.au/file.php?id=193 |title=Derwent Estuary&nbsp;– Water Quality Improvement Plan for Heavy Metals |date=June 2007 |publisher=Derwent Estuary Program |access-date=July 11, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20120321090648/http://www.derwentestuary.org.au/file.php?id=193 |archive-date=March 21, 2012 }}</ref> the zinc works at [[Lutana]] is the largest exporter in Tasmania, generating 2.5% of the state's [[Gross domestic product|GDP]], and producing more than 250,000 tonnes of zinc per year.<ref>{{cite web|title=The Zinc Works|url=http://www.tchange.com.au/resources/zinifex_smelter.html|publisher=TChange|access-date=July 11, 2009|url-status=live|archive-url=https://web.archive.org/web/20090427031313/http://www.tchange.com.au/resources/zinifex_smelter.html|archive-date=April 27, 2009}}</ref>|alt=A panorama featuring a large industrial plant on a sea side, in front of mountains.}}
[[soil contamination|Soils contaminated]] with zinc from mining, refining, or fertilizing with zinc-bearing sludge can contain several grams of zinc per kilogram of dry soil. Levels of zinc in excess of 500&nbsp;ppm in soil interfere with the ability of plants to absorb other [[Dietary mineral|essential metals]], such as iron and [[manganese]]. Zinc levels of 2000&nbsp;ppm to 180,000&nbsp;ppm (18%) have been recorded in some soil samples.<ref name="Emsley2001p504" />
==Applications==
Major applications of zinc include, with percentages given for the US<ref name="USGS-yb2006" />
# [[Galvanization|Galvanizing]] (55%)
# [[Brass]] and [[bronze]] (16%)
# Other alloys (21%)
# Miscellaneous (8%)
===Anti-corrosion and batteries===
[[File:Feuerverzinkte Oberfläche.jpg|thumb|Hot-dip handrail [[galvanization|galvanized]] crystalline surface|alt=Merged elongated crystals of various shades of gray.]]
[[File:Zinkanode neu.jpg|thumb|Zinc [[sacrificial anode]]]]
Zinc is most commonly used as an anti-[[corrosion]] agent,<ref name="Greenwood1997p1203">{{harvnb|Greenwood|Earnshaw|1997|p=1203}}</ref> and galvanization (coating of [[iron]] or [[steel]]) is the most familiar form. In 2009 in the United States, 55% or 893,000 tons of the zinc metal was used for galvanization.<ref name="USGS-yb2006">{{cite web |date=February 2010 |url=http://minerals.usgs.gov/minerals/pubs/commodity/zinc/myb1-2009-zinc.pdf|access-date=June 6, 2001 |title=Zinc: World Mine Production (zinc content of concentrate) by Country |work=2009 Minerals Yearbook: Zinc |publisher=United States Geological Survey |location=Washington, D.C. |url-status=live|archive-url=https://web.archive.org/web/20110608154555/http://minerals.usgs.gov/minerals/pubs/commodity/zinc/myb1-2009-zinc.pdf|archive-date=June 8, 2011}}</ref>
Zinc is more reactive than iron or steel and thus will attract almost all local oxidation until it completely corrodes away.<ref name="Stwertka1998p99">{{harvnb|Stwertka|1998|p=99}}</ref> A protective surface layer of oxide and carbonate ({{chem|Zn|5|(OH)|6|(CO|3|)|2|)}} forms as the zinc corrodes.<ref name="Lehto1968p829">{{harvnb|Lehto|1968|p=829}}</ref> This protection lasts even after the zinc layer is scratched but degrades through time as the zinc corrodes away.<ref name="Lehto1968p829" /> The zinc is applied electrochemically or as molten zinc by [[hot-dip galvanizing]] or spraying. Galvanization is used on chain-link fencing, guard rails, suspension bridges, lightposts, metal roofs, heat exchangers, and car bodies.<ref name="Emsley2001p503">{{harvnb|Emsley|2001|p=503}}</ref>
The relative reactivity of zinc and its ability to attract oxidation to itself makes it an efficient [[sacrificial anode]] in [[cathodic protection]] (CP). For example, cathodic protection of a buried pipeline can be achieved by connecting anodes made from zinc to the pipe.<ref name="Lehto1968p829" /> Zinc acts as the [[anode]] (negative terminus) by slowly corroding away as it passes electric current to the steel pipeline.<ref name="Lehto1968p829" />{{efn|Electric current will naturally flow between zinc and steel but in some circumstances inert anodes are used with an external DC source.}} Zinc is also used to cathodically protect metals that are exposed to sea water.<ref>{{Cite journal|title=A comparative study of the electrochemical behaviour of Algerian zinc and a zinc from a commercial sacrificial anode|last=Bounoughaz|first=M.|author2=Salhi, E.|author3=Benzine, K.|author4=Ghali E.|author5=Dalard F.|journal=Journal of Materials Science|volume =38|issue=6|pages=1139–1145|doi=10.1023/A:1022824813564|date=2003|bibcode = 2003JMatS..38.1139B |s2cid=135744939}}</ref> A zinc disc attached to a ship's iron rudder will slowly corrode while the rudder stays intact.<ref name="Stwertka1998p99" /> Similarly, a zinc plug attached to a propeller or the metal protective guard for the keel of the ship provides temporary protection.
With a [[standard electrode potential]] (SEP) of −0.76 [[volt]]s, zinc is used as an anode material for batteries. (More reactive lithium (SEP −3.04 V) is used for anodes in [[Lithium battery|lithium batteries]] ). Powdered zinc is used in this way in [[alkaline battery|alkaline batteries]] and the case (which also serves as the anode) of [[Zinc–carbon battery|zinc–carbon batteries]] is formed from sheet zinc.<ref>{{Cite book|first=Jürgen O.|last=Besenhard|title=Handbook of Battery Materials|publisher=Wiley-VCH|isbn=978-3-527-29469-5|date=1999|bibcode=1999hbm..book.....B}}</ref><ref>{{Cite journal|doi=10.1016/0378-7753(95)02242-2|date=1995|title=Recycling zinc batteries: an economical challenge in consumer waste management|first=J.-P.|last=Wiaux|author2=Waefler, J. -P. |journal=Journal of Power Sources|volume=57|issue=1–2|pages=61–65|bibcode = 1995JPS....57...61W }}</ref> Zinc is used as the anode or fuel of the [[zinc–air battery]]/fuel cell.<ref>{{Cite book|chapter=A design guide for rechargeable zinc–air battery technology|last=Culter|first=T.|doi=10.1109/SOUTHC.1996.535134|title=Southcon/96. Conference Record|isbn=978-0-7803-3268-3|date=1996|page=616|s2cid=106826667}}</ref><ref>{{cite web|url=http://www.electric-fuel.com/evtech/papers/paper11-1-98.pdf |title=Zinc Air Battery-Battery Hybrid for Powering Electric Scooters and Electric Buses |first=Jonathan |last=Whartman |author2=Brown, Ian |publisher=The 15th International Electric Vehicle Symposium |access-date=October 8, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20060312003601/http://www.electric-fuel.com/evtech/papers/paper11-1-98.pdf |archive-date=March 12, 2006 }}</ref><ref>{{cite journal|title=A refuelable zinc/air battery for fleet electric vehicle propulsion|journal=NASA Sti/Recon Technical Report N|volume=96|pages=11394|last=Cooper|first=J. F.|author2=Fleming, D.|author3=Hargrove, D.|author4=Koopman, R.|author5=Peterman, K|publisher=Society of Automotive Engineers future transportation technology conference and exposition|osti = 82465|bibcode=1995STIN...9611394C|year=1995}}</ref> The [[Zinc–cerium battery|zinc-cerium]] [[redox flow battery]] also relies on a zinc-based negative half-cell.<ref name="Xie1">{{cite journal|last1=Xie|first1=Z.|last2=Liu|first2=Q.|last3=Chang|first3=Z.|last4=Zhang|first4=X.|title=The developments and challenges of cerium half-cell in zinc–cerium redox flow battery for energy storage|journal=Electrochimica Acta|date=2013|volume=90|pages=695–704|doi=10.1016/j.electacta.2012.12.066}}</ref>
===Alloys===
A widely used zinc alloy is brass, in which copper is alloyed with anywhere from 3% to 45% zinc, depending upon the type of brass.<ref name="Lehto1968p829" /> Brass is generally more [[ductile]] and stronger than copper, and has superior [[corrosion resistance]].<ref name="Lehto1968p829" /> These properties make it useful in communication equipment, hardware, musical instruments, and water valves.<ref name="Lehto1968p829" />
[[File:Microstructure of rolled and annealed brass; magnification 400X.jpg|thumb|left|Cast brass microstructure at magnification 400x|alt=A mosaica pattern composed of components having various shapes and shades of brown.]]
Other widely used zinc alloys include [[nickel silver]], typewriter metal, soft and aluminium [[solder]], and commercial [[bronze]].<ref name="CRCp4-41" /> Zinc is also used in contemporary pipe organs as a substitute for the traditional lead/tin alloy in pipes.<ref>{{Cite book|first=Douglas Earl|last=Bush|author2=Kassel, Richard |title=The Organ: An Encyclopedia|isbn=978-0-415-94174-7|url=https://books.google.com/books?id=cgDJaeFFUPoC|publisher=Routledge|date=2006|page=679}}</ref> Alloys of 85–88% zinc, 4–10% copper, and 2–8% aluminium find limited use in certain types of machine bearings. Zinc has been the primary metal in [[Lincoln cent|American one cent coins]] (pennies) since 1982.<ref name="onecent">{{cite web|url=http://www.usmint.gov/about_the_mint/?action=coin_specifications|publisher=United States Mint|access-date=October 8, 2008|title=Coin Specifications|url-status=live|archive-url=https://web.archive.org/web/20150218061037/http://www.usmint.gov/about_the_mint/?action=coin_specifications|archive-date=February 18, 2015}}</ref> The zinc core is coated with a thin layer of copper to give the appearance of a copper coin. In 1994, {{convert|33200|t|ST}} of zinc were used to produce 13.6&nbsp;billion pennies in the United States.<ref name="USGS-yb1994">{{cite web|url=http://minerals.usgs.gov/minerals/pubs/commodity/zinc/720494.pdf|publisher=United States Geological Survey|title=Mineral Yearbook 1994: Zinc|first=Stephen M.|last=Jasinski|access-date=November 13, 2008|url-status=live|archive-url=https://web.archive.org/web/20081029065604/http://minerals.usgs.gov/minerals/pubs/commodity/zinc/720494.pdf|archive-date=October 29, 2008}}</ref>
Alloys of zinc with small amounts of copper, aluminium, and magnesium are useful in [[die casting]] as well as [[spin casting]], especially in the automotive, electrical, and hardware industries.<ref name="CRCp4-41" /> These alloys are marketed under the name [[Zamak]].<ref>{{cite web|url=http://www.eazall.com/diecastalloys.aspx|title=Diecasting Alloys|publisher=Eastern Alloys|access-date=January 19, 2009|location=Maybrook, NY|url-status=live|archive-url=https://web.archive.org/web/20081225003739/http://www.eazall.com/diecastalloys.aspx|archive-date=December 25, 2008}}</ref> An example of this is [[zinc aluminium]]. The low melting point together with the low [[viscosity]] of the alloy makes possible the production of small and intricate shapes. The low working temperature leads to rapid cooling of the cast products and fast production for assembly.<ref name="CRCp4-41" /><ref>{{Cite journal|first=D.|last=Apelian|author2=Paliwal, M. |author3=Herrschaft, D. C. |title=Casting with Zinc Alloys|journal=Journal of Metals|volume=33|issue=11|date=1981|pages =12–19|doi=10.1007/bf03339527|bibcode = 1981JOM....33k..12A }}</ref> Another alloy, marketed under the brand name Prestal, contains 78% zinc and 22% aluminium, and is reported to be nearly as strong as steel but as malleable as plastic.<ref name="CRCp4-41" /><ref>{{Cite book|url=https://books.google.com/books?id=s0i32LSfrJ4C&pg=PA157|page=157|title=Materials for automobile bodies|author=Davies, Geoff|publisher=Butterworth-Heinemann|date=2003|isbn=978-0-7506-5692-4}}</ref> This [[superplasticity]] of the alloy allows it to be molded using die casts made of ceramics and cement.<ref name="CRCp4-41" />
Similar alloys with the addition of a small amount of lead can be cold-rolled into sheets. An alloy of 96% zinc and 4% aluminium is used to make stamping dies for low production run applications for which ferrous metal dies would be too expensive.<ref name="samans">{{Cite book|last=Samans|first=Carl Hubert|title=Engineering Metals and Their Alloys|publisher=Macmillan Co.|date=1949}}</ref> For building facades, roofing, and other applications for [[sheet metal]] formed by [[deep drawing]], [[roll forming]], or [[bending (metalworking)|bending]], zinc alloys with [[titanium]] and copper are used.<ref name="ZincCorr">{{Cite book|chapter-url=https://books.google.com/books?id=C-pAiedmqp8C|title=Corrosion Resistance of Zinc and Zinc Alloys|first=Frank|last=Porter|publisher =CRC Press|date=1994|isbn=978-0-8247-9213-8|chapter=Wrought Zinc|pages=6–7}}</ref> Unalloyed zinc is too brittle for these manufacturing processes.<ref name="ZincCorr" />
As a dense, inexpensive, easily worked material, zinc is used as a [[lead]] replacement. In the wake of [[Lead poisoning|lead concerns]], zinc appears in weights for various applications ranging from fishing<ref>{{cite book|author=McClane, Albert Jules|author2=Gardner, Keith|name-list-style=amp|title=The Complete book of fishing: a guide to freshwater, saltwater & big-game fishing|url=https://books.google.com/books?id=b3nWAAAAMAAJ|access-date=June 26, 2012|date=1987|publisher=Gallery Books|isbn=978-0-8317-1565-6|url-status=live|archive-url=https://web.archive.org/web/20121115010409/http://books.google.com/books?id=b3nWAAAAMAAJ|archive-date=November 15, 2012}}</ref> to [[tire balance]]s and flywheels.<ref name="minrecall">{{cite web
|url=http://www.minourausa.com/english/support-e/recall-e.html
|title=Cast flywheel on old Magturbo trainer has been recalled since July 2000
|work=Minoura
|url-status=dead
|archive-url=https://web.archive.org/web/20130323175731/http://www.minourausa.com/english/support-e/recall-e.html
|archive-date=March 23, 2013
}}</ref>
[[Cadmium zinc telluride]] (CZT) is a [[semiconductor|semiconductive]] alloy that can be divided into an array of small sensing devices.<ref name="Katz2002" /> These devices are similar to an [[integrated circuit]] and can detect the energy of incoming [[gamma ray]] photons.<ref name="Katz2002" /> When behind an absorbing mask, the CZT sensor array can determine the direction of the rays.<ref name="Katz2002">{{Cite book|title=The Biggest Bangs|last=Katz|first=Johnathan I.|page=[https://archive.org/details/biggestbangsmyst00katz_0/page/18 18]|publisher=[[Oxford University Press]]|date=2002|isbn=978-0-19-514570-0|url=https://archive.org/details/biggestbangsmyst00katz_0/page/18}}</ref>
===Other industrial uses===
[[File:Zinc oxide.jpg|thumb|Zinc oxide is used as a white [[pigment]] in [[paint]]s.|alt=White powder on a glass plate]]
Roughly one quarter of all zinc output in the United States in 2009 was consumed in zinc compounds;<ref name="USGS-yb2006" /> a variety of which are used industrially. Zinc oxide is widely used as a white pigment in paints and as a [[catalyst]] in the manufacture of rubber to disperse heat. Zinc oxide is used to protect rubber polymers and plastics from [[ultraviolet radiation]] (UV).<ref name="Emsley2001p503" /> The [[semiconductor]] properties of zinc oxide make it useful in [[varistor]]s and photocopying products.<ref>{{Cite book|last=Zhang|first=Xiaoge Gregory|title=Corrosion and Electrochemistry of Zinc|publisher=Springer|date=1996|page=93|isbn=978-0-306-45334-2|url=https://books.google.com/books?id=Qmf4VsriAtMC}}</ref> The [[zinc zinc-oxide cycle]] is a two step [[Thermochemistry|thermochemical]] process based on zinc and zinc oxide for [[hydrogen production]].<ref>{{cite web|url=http://www.hydrogen.energy.gov/pdfs/review06/pd_10_weimer.pdf|title=Development of Solar-powered Thermochemical Production of Hydrogen from Water|last=Weimer|first=Al|date=May 17, 2006|access-date=January 10, 2009|publisher=[[U.S. Department of Energy]]|url-status=live|archive-url=https://web.archive.org/web/20090205122514/http://www.hydrogen.energy.gov/pdfs/review06/pd_10_weimer.pdf|archive-date=February 5, 2009}}</ref>
[[Zinc chloride]] is often added to lumber as a [[fire retardant]]<ref name="Heiserman1992p124">{{harvnb|Heiserman|1992|p=124}}</ref> and sometimes as a wood [[preservative]].<ref>{{cite web|title=Wood preservatives |last=Blew|first=Joseph Oscar|date=1953|publisher=Department of Agriculture, Forest Service, Forest Products Laboratory|url=http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/816/FPL_D149ocr.pdf |hdl=1957/816|url-status=live|archive-url=https://web.archive.org/web/20120114143025/http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/816/FPL_D149ocr.pdf|archive-date=January 14, 2012}}</ref> It is used in the manufacture of other chemicals.<ref name="Heiserman1992p124" /> [[Zinc methyl]] ({{chem|Zn(CH<sub>3</sub>)|2}}) is used in a number of organic [[organic synthesis|syntheses]].<ref>{{Cite journal|first=Edward|last=Frankland|author-link=Edward Frankland|journal=[[Liebigs Annalen|Liebig's Annalen der Chemie und Pharmacie]]|title=Notiz über eine neue Reihe organischer Körper, welche Metalle, Phosphor u. s. w. enthalten|date=1849|volume=71|issue=2|pages=213–216|doi=10.1002/jlac.18490710206|language=de|url=https://zenodo.org/record/1427026}}</ref> [[Zinc sulfide]] (ZnS) is used in [[luminescence|luminescent]] pigments such as on the hands of clocks, [[X-ray]] and television screens, and [[luminous paint]]s.<ref name="CRCp4-42">{{harvnb|CRC|2006|p='''4'''{{hyphen}}42<!-- sic "hyphen -" ; not a range!-->}}</ref> Crystals of ZnS are used in [[laser]]s that operate in the mid-[[infrared]] part of the spectrum.<ref>{{Cite book|last=Paschotta|first=Rüdiger|title=Encyclopedia of Laser Physics and Technology|publisher=Wiley-VCH|date=2008|page=798|isbn=978-3-527-40828-3|url=https://books.google.com/books?id=2p9WvgAACAAJ}}</ref> [[Zinc sulfate]] is a chemical in [[dye]]s and pigments.<ref name= "Heiserman1992p124" /> [[Zinc pyrithione]] is used in [[antifouling]] paints.<ref>{{Cite journal|journal=Environment International|volume=30|date=2004|issue=2|pages=235–248|doi=10.1016/S0160-4120(03)00176-4 |pmid=14749112|title=Worldwide occurrence and effects of antifouling paint booster biocides in the aquatic environment: a review|first=I. K.|last=Konstantinou|author2=Albanis, T. A. |bibcode=2004EnInt..30..235K }}</ref>
Zinc powder is sometimes used as a [[propellant]] in [[model rocket]]s.<ref name="ZnS" /> When a compressed mixture of 70% zinc and 30% [[sulfur]] powder is ignited there is a violent chemical reaction.<ref name="ZnS" /> This produces zinc sulfide, together with large amounts of hot gas, heat, and light.<ref name="ZnS">{{cite web|url=http://www.angelo.edu/faculty/kboudrea/demos/zinc_sulfur/zinc_sulfur.htm|title=Zinc + Sulfur|last=Boudreaux|first=Kevin A.|publisher=Angelo State University|access-date=October 8, 2008|url-status=live|archive-url=https://web.archive.org/web/20081202034703/http://www.angelo.edu/faculty/kboudrea/demos/zinc_sulfur/zinc_sulfur.htm|archive-date=December 2, 2008}}</ref>
Zinc sheet metal is used as a durable covering for roofs, walls, and countertops, the last often seen in [[bistro]]s and [[oyster bar]]s, and is known for the rustic look imparted by its surface [[oxidation]] in use to a blue-gray [[patina]] and susceptibility to scratching.<ref>{{cite web |url=https://rolled.zinc.org/ |title=Rolled and Titanium Zinc Sheet |access-date=October 21, 2022}}</ref><ref>{{cite web |url=https://www.hunker.com/13466339/things-you-should-know-about-zinc-countertops |title=Things You Should Know About Zinc Countertops |access-date=October 21, 2022}}</ref><ref>{{cite web | url=https://www.masterclass.com/articles/guide-to-zinc-countertops |title=Guide to Zinc Countertops: Benefits of Zinc Kitchen Counters |access-date=October 21, 2022}}</ref><ref>{{cite web|title=Technical Information|date=2008|publisher=Zinc Counters|url=http://www.zinccounters.co.uk/html/tech/tech.htm|access-date=November 29, 2008|url-status=dead|archive-url=https://web.archive.org/web/20081121002508/http://www.zinccounters.co.uk/html/tech/tech.htm|archive-date=November 21, 2008}}</ref>
{{chem|64|Zn}}, the most abundant isotope of zinc, is very susceptible to [[neutron activation]], being [[Nuclear transmutation|transmuted]] into the highly radioactive {{chem|65|Zn}}, which has a half-life of 244 days and produces intense [[gamma ray|gamma radiation]]. Because of this, zinc oxide used in nuclear reactors as an anti-corrosion agent is depleted of {{chem|64|Zn}} before use, this is called [[depleted zinc oxide]]. For the same reason, zinc has been proposed as a [[Salted bomb|salting]] material for [[nuclear weapon]]s ([[cobalt]] is another, better-known salting material).<ref name="Win2003" /> A jacket of [[Isotope separation|isotopically enriched]] {{chem|64|Zn}} would be irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, forming a large amount of {{chem|65|Zn}} significantly increasing the radioactivity of the weapon's [[Nuclear fallout|fallout]].<ref name="Win2003" /> Such a weapon is not known to have ever been built, tested, or used.<ref name="Win2003">{{Cite journal|title=Weapons of Mass Destruction|first=David Tin|last=Win|author2=Masum, Al|url=http://www.journal.au.edu/au_techno/2003/apr2003/aujt6-4_article07.pdf|date=2003|journal=Assumption University Journal of Technology|volume=6|issue=4|page=199|publisher=Assumption University|access-date=April 6, 2009|url-status=live|archive-url=https://web.archive.org/web/20090326001457/http://www.journal.au.edu/au_techno/2003/apr2003/aujt6-4_article07.pdf|archive-date=March 26, 2009}}</ref>
{{chem|65|Zn}} is used as a [[isotopic tracer|tracer]] to study how alloys that contain zinc wear out, or the path and the role of zinc in organisms.<ref>{{cite book|url=http://www.encyclopedia.com/doc/1G2-3427000114.html|isbn=978-0-7876-2846-8|publisher=U. X. L. /Gale|date=1999|title=Chemical Elements: From Carbon to Krypton|author=David E. Newton|access-date=April 6, 2009|url-status=live|archive-url=https://web.archive.org/web/20080710132328/http://www.encyclopedia.com/doc/1G2-3427000114.html|archive-date=July 10, 2008}}</ref>
Zinc dithiocarbamate complexes are used as agricultural [[fungicide]]s; these include [[Zineb]], Metiram, Propineb and Ziram.<ref>{{Cite book|url=https://books.google.com/books?id=cItuoO9zSjkC&pg=PA591|title=Ullmann's Agrochemicals|date=2007|publisher=Wiley-Vch (COR)|isbn=978-3-527-31604-5|pages=591–592}}{{Dead link|date=June 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Zinc naphthenate is used as wood preservative.<ref>{{Cite book|title=Primary Wood Processing: Principles and Practice| last=Walker|first =J. C. F.|date=2006|publisher=Springer|isbn=978-1-4020-4392-5|page=317}}</ref> Zinc in the form of [[Zinc dithiophosphate|ZDDP]], is used as an anti-wear additive for metal parts in engine oil.<ref>{{cite web|title=ZDDP Engine Oil&nbsp;– The Zinc Factor|url=http://www.mustangmonthly.com/techarticles/mump_0907_zddp_zinc_additive_engine_oil/index.html|publisher=Mustang Monthly|access-date=September 19, 2009|url-status=live|archive-url=https://web.archive.org/web/20090912041431/http://www.mustangmonthly.com/techarticles/mump_0907_zddp_zinc_additive_engine_oil/index.html|archive-date=September 12, 2009}}</ref>
===Organic chemistry===
[[File:DiphenylzincCarbonylAddition.png|thumb|upright=1.6|Enantioselective addition of diphenylzinc to an aldehyde<ref>{{cite journal | doi = 10.1002/anie.200600741 | title = From Aryl Bromides to Enantioenriched Benzylic Alcohols in a Single Flask: Catalytic Asymmetric Arylation of Aldehydes | date = 2006 | last1 = Kim | first1 = Jeung Gon | last2 = Walsh | first2 = Patrick J. | journal = Angewandte Chemie International Edition | volume = 45 | issue = 25 | pages = 4175–4178 | pmid=16721894| doi-access = free }}</ref>]]
[[Organozinc compound|Organozinc]] chemistry is the science of compounds that contain carbon-zinc bonds, describing the physical properties, synthesis, and chemical reactions. Many organozinc compounds are commercially important.<ref>{{cite book | doi = 10.1002/0471264180.or066.01 | title = The Allylic Trihaloacetimidate Rearrangement | series = Organic Reactions | date = 2005 | last1 = Overman | first1 = Larry E. | last2 = Carpenter | first2 = Nancy E. | isbn = 978-0-471-26418-7 | volume = 66 | pages =1–107}}</ref><ref>{{cite book | isbn = 978-0-470-09337-5 | url = https://books.google.com/books?id=Y3wYEmIHlqUC | title = The Chemistry of Organozinc Compounds: R-Zn | last1 = Rappoport | first1 = Zvi | last2 = Marek | first2 = Ilan | date = December 17, 2007 | publisher=John Wiley & Sons | url-status=live | archive-url = https://web.archive.org/web/20160414165728/https://books.google.com/books?id=Y3wYEmIHlqUC | archive-date = April 14, 2016 | df = mdy-all }}</ref><ref>{{cite book | isbn = 978-0-19-850121-3 | url = https://books.google.com/books?id=UH5tQgAACAAJ | title = Organozinc reagents: A practical approach | last1 = Knochel | first1 = Paul | last2 = Jones | first2 = Philip | date = 1999 | publisher=Oxford University Press | url-status=live | archive-url = https://web.archive.org/web/20160414152600/https://books.google.com/books?id=UH5tQgAACAAJ | archive-date = April 14, 2016 | df = mdy-all }}</ref><ref>{{cite book | url = https://books.google.com/books?id=hgUqZkG23PAC | isbn = 978-3-13-103061-0 | title = Synthetic Methods of Organometallic and Inorganic Chemistry: Catalysis | last1 = Herrmann | first1 = Wolfgang A. | date = January 2002 | publisher = Georg Thieme Verlag | url-status=live | archive-url = https://web.archive.org/web/20160414190931/https://books.google.com/books?id=hgUqZkG23PAC | archive-date = April 14, 2016 | df = mdy-all }}</ref> Among important applications are:
* The Frankland-Duppa Reaction in which an [[oxalate]] [[ester]] (ROCOCOOR) reacts with an [[alkyl halide]] R'X, zinc and [[hydrochloric acid]] to form α-hydroxycarboxylic esters RR'COHCOOR<ref>E. Frankland, Ann. 126, 109 (1863)</ref><ref>E. Frankland, B. F. Duppa, Ann. 135, 25 (1865)</ref>
* Organozincs have similar reactivity to [[Grignard reagent|Grignard reagents]] but are much less nucleophilic, and they are expensive and difficult to handle. Organozincs typically perform nucleophilic addition on electrophiles such as [[aldehydes]], which are then reduced to [[Alcohol (chemistry)|alcohols]]. Commercially available diorganozinc compounds include [[dimethylzinc]], [[diethylzinc]] and diphenylzinc. Like Grignard reagents, organozincs are commonly produced from [[organobromine compound|organobromine]] precursors.
Zinc has found many uses in catalysis in organic synthesis including [[asymmetric reaction|enantioselective synthesis]], being a cheap and readily available alternative to precious metal complexes. Quantitative results (yield and [[enantiomeric excess]]) obtained with chiral zinc catalysts can be comparable to those achieved with palladium, ruthenium, iridium and others.<ref>{{cite journal|last1=Łowicki|first1=Daniel|author2=Baś, Sebastian|author3=Mlynarski, Jacek|title=Chiral zinc catalysts for asymmetric synthesis|journal=Tetrahedron|date=2015|volume=71|issue=9|pages=1339–1394|doi=10.1016/j.tet.2014.12.022}}</ref>
===Dietary supplement===
[[File:Zinc pills.jpg|thumb|[[Zinc gluconate]] supplement pills]]
[[File:Zinc gluconate structure.svg|thumb|upright=1.35|[[Zinc gluconate]] is one compound used for the delivery of zinc as a [[dietary supplement]].|alt=Skeletal chemical formula of a planar compound featuring a Zn atom in the center, symmetrically bonded to four oxygens. Those oxygens are further connected to linear COH chains.]]
{{see also|Zinc sulfate (medical use)|Zinc gluconate}}
In most single-tablet, over-the-counter, daily vitamin and [[Dietary mineral|mineral]] supplements, zinc is included in such forms as [[zinc oxide]], [[zinc acetate]], [[zinc gluconate]], or zinc amino acid chelate.<ref name="DiSilvestro2004">{{Cite book|title=Handbook of Minerals as Nutritional Supplements|last=DiSilvestro|first=Robert A.|date=2004|publisher=CRC Press|isbn=978-0-8493-1652-4|pages=135, 155}}</ref><ref name="USgov">{{cite report
|url=https://clinicaltrials.gov/ct2/show/NCT01791608
|title=Zinc Sulphate vs. Zinc Amino Acid Chelate (ZAZO)
|via=U.S. National Library of Medecine
|date=February 13, 2013
|publisher=USA Government
|access-date=April 6, 2022|last1=Sanchez
|first1=Juliana
|id=NCT01791608
}}</ref>
Generally, zinc supplement is recommended where there is high risk of zinc deficiency (such as low and middle income countries) as a preventive measure.<ref>{{cite journal |last1=Mayo-Wilson |first1=E |last2=Junior |first2=JA |last3=Imdad |first3=A |last4=Dean |first4=S |last5=Chan |first5=XH |last6=Chan |first6=ES |last7=Jaswal |first7=A |last8=Bhutta |first8=ZA |title=Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years of age. |journal=The Cochrane Database of Systematic Reviews |date=May 15, 2014 |issue=5 |pages=CD009384 |doi=10.1002/14651858.CD009384.pub2 |pmid=24826920}}</ref> Although zinc sulfate is a commonly used zinc form, zinc citrate, gluconate and picolinate may be valid options as well. These forms are better absorbed than zinc oxide.<ref name="Zincposology2019">{{cite journal|title=Dietary vs. pharmacological doses of zinc: A clinical review. |journal=Clin Nutr. |volume=130 |issue=5 |doi=10.1016/j.clnu.2019.06.024|pmid=31303527|year=2019 |vauthors=Santos HO, Teixeira FJ, Schoenfeld BJ |pages=1345–1353|s2cid=196616666 }}</ref>
====Gastroenteritis====
Zinc is an inexpensive and effective part of treatment of [[diarrhea]] among children in the developing world. Zinc becomes depleted in the body during diarrhea and replenishing zinc with a 10- to 14-day course of treatment can reduce the duration and severity of diarrheal episodes and may also prevent future episodes for as long as three months.<ref>{{cite journal|title=Therapeutic effects of oral zinc in acute and persistent diarrhea in children in developing countries: pooled analysis of randomized controlled trials|pmid=11101480|date=2000|vauthors=Bhutta ZA, Bird SM, Black RE, Brown KH, Gardner JM, Hidayat A, Khatun F, Martorell R, Ninh NX, Penny ME, Rosado JL, Roy SK, Ruel M, Sazawal S, Shankar A<!--|collaboration=The Zinc Investigators’ Collaborative Group-->|display-authors=8|volume=72|issue=6 |pages=1516–1522|journal=The American Journal of Clinical Nutrition |doi=10.1093/ajcn/72.6.1516|doi-access=free}}</ref> [[Gastroenteritis]] is strongly attenuated by ingestion of zinc, possibly by direct antimicrobial action of the ions in the [[gastrointestinal tract]], or by the absorption of the zinc and re-release from immune cells (all [[granulocyte]]s secrete zinc), or both.<ref>{{cite journal|last=Aydemir |first=T. B.|author2=Blanchard, R. K. |author3=Cousins, R. J. |date=2006|title=Zinc supplementation of young men alters metallothionein, zinc transporter, and cytokine gene expression in leukocyte populations |journal=PNAS|pmid=16434472|volume=103|issue=6|pmc=1413653|doi=10.1073/pnas.0510407103|bibcode = 2006PNAS..103.1699A |pages=1699–704|doi-access=free}}</ref><ref>{{cite journal |last=Valko|first=M. |author2=Morris, H. |author3=Cronin, M. T. D. |date=2005|title=Metals, Toxicity and Oxidative stress|journal=Current Medicinal Chemistry |issue=10 |volume=12 |doi=10.2174/0929867053764635 |pmid=15892631 |pages=1161–208 |url=http://webmail.stuba.sk/~marian.valko/PDF/CMC_2005.pdf|url-status=dead|archive-url=https://web.archive.org/web/20170808080110/http://webmail.stuba.sk/~marian.valko/PDF/CMC_2005.pdf |archive-date=August 8, 2017}}</ref>
====Common cold{{anchor|Common cold}}====
{{Excerpt|Zinc and the common cold}}
====Weight gain====
{{See also|Zinc deficiency#Appetite}}
Zinc deficiency may lead to loss of appetite.<ref>{{cite journal | vauthors = Suzuki H, Asakawa A, Li JB, Tsai M, Amitani H, Ohinata K, Komai M, Inui A | title = Zinc as an appetite stimulator – the possible role of zinc in the progression of diseases such as cachexia and sarcopenia | journal = Recent Patents on Food, Nutrition & Agriculture | volume = 3 | issue = 3 | pages = 226–231 | date =2011 | pmid = 21846317 | doi = 10.2174/2212798411103030226 }}</ref> The use of zinc in the treatment of anorexia has been advocated since 1979. At least 15 clinical trials have shown that zinc improved weight gain in anorexia. A 1994 trial showed that zinc doubled the rate of body mass increase in the treatment of anorexia nervosa. Deficiency of other nutrients such as tyrosine, tryptophan and thiamine could contribute to this phenomenon of "malnutrition-induced malnutrition".<ref name="Zincappetitereview">{{cite journal|title=Neurobiology of Zinc-Influenced Eating Behavior |journal=The Journal of Nutrition|volume=130|issue=5|pages=1493S–1499S|doi=10.1093/jn/130.5.1493S|pmid=10801965|year=2000|last1=Shay|first1=Neil F.|last2=Mangian|first2=Heather F.|doi-access=free}}</ref>
A meta-analysis of 33 prospective intervention trials regarding zinc supplementation and its effects on the growth of children in many countries showed that zinc supplementation alone had a statistically significant effect on linear growth and body weight gain, indicating that other deficiencies that may have been present were not responsible for growth retardation.<ref name="Zincappetitereview2">{{cite journal|title=Zinc|journal=StatPearls [Internet]|pmid=31613478|year=2019|vauthors=Rabinovich D, Smadi Y}}</ref>
====Other====
People taking zinc supplements may slow down the progress to [[age-related macular degeneration]].<ref>{{cite journal |vauthors=Evans JR, Lawrenson JG |date=13 Sep 2023 |title=Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration |journal=Cochrane Database Syst Rev |doi=10.1002/14651858.CD000254.pub5 |pmid=37702300|pmc=10498493 }}</ref> Zinc supplement is an effective treatment for [[acrodermatitis enteropathica]], a genetic disorder affecting zinc absorption that was previously fatal to affected infants.<ref name="Emsley2001p501" /> Zinc deficiency has been associated with [[major depressive disorder]] (MDD), and zinc supplements may be an effective treatment.<ref name="pmid23567517">{{cite journal | vauthors = Swardfager W, Herrmann N, McIntyre RS, Mazereeuw G, Goldberger K, Cha DS, Schwartz Y, Lanctôt KL | title = Potential roles of zinc in the pathophysiology and treatment of major depressive disorder | journal = Neurosci. Biobehav. Rev. | volume = 37 | issue = 5 | pages = 911–929 | date = June 2013 | pmid = 23567517 | doi = 10.1016/j.neubiorev.2013.03.018 | s2cid = 1725139 }}</ref> Zinc may help individuals sleep more.<ref name="Zinc & sleep 2017 review" />
===Topical use===
{{further|Zinc oxide#Medicine}}
[[Topical administration|Topical preparations]] of zinc include those used on the skin, often in the form of [[zinc oxide]]. Zinc oxide is generally recognized by the FDA as safe and effective<ref>{{Cite journal |last=Research |first=Center for Drug Evaluation and |date=November 16, 2021 |title=Questions and Answers: FDA posts deemed final order and proposed order for over-the-counter sunscreen |url=https://www.fda.gov/drugs/understanding-over-counter-medicines/questions-and-answers-fda-posts-deemed-final-order-and-proposed-order-over-counter-sunscreen |journal=FDA |language=en}}</ref> and is considered a very photo-stable.<ref>{{Citation |last1=Chauhan |first1=Ravi |title=Advancing of Zinc Oxide Nanoparticles for Cosmetic Applications |date=2021 |url=https://doi.org/10.1007/978-981-15-6453-6_100-1 |work=Handbook of Consumer Nanoproducts |pages=1–16 |editor-last=Mallakpour |editor-first=Shadpour |place=Singapore |publisher=Springer |language=en |doi=10.1007/978-981-15-6453-6_100-1 |isbn=978-981-15-6453-6 |access-date=October 31, 2022 |last2=Kumar |first2=Amit |last3=Tripathi |first3=Ramna |last4=Kumar |first4=Akhilesh |s2cid=245778598 |editor2-last=Hussain |editor2-first=Chaudhery Mustansar}}</ref> Zinc oxide is one of the most common active ingredients formulated into a sunscreen to mitigate [[sunburn]].<ref name="Emsley2001p501" /> Applied thinly to a baby's diaper area ([[perineum]]) with each diaper change, it can protect against [[diaper rash]].<ref name="Emsley2001p501" />
Chelated zinc is used in toothpastes and mouthwashes to prevent [[halitosis|bad breath]]; zinc citrate helps reduce the build-up of [[Calculus (dental)|calculus]] (tartar).<ref>{{Cite journal|volume =30|issue =5|pages=427–434|date=2003|title=The effects of a new mouthrinse containing chlorhexidine, cetylpyridinium chloride and zinc lactate on the microflora of oral halitosis patients: a dual-centre, double-blind placebo-controlled study|author=Roldán, S.|author2=Winkel, E. G.|author3=Herrera, D.|author4=Sanz, M.|author5=Van Winkelhoff, A. J.|doi=10.1034/j.1600-051X.2003.20004.x|pmid =12716335|journal =Journal of Clinical Periodontology}}</ref><ref>{{Cite web|title=Toothpastes|url=https://www.ada.org/en/member-center/oral-health-topics/toothpastes|access-date=September 27, 2020|website=www.ada.org|archive-date=March 5, 2016|archive-url=https://web.archive.org/web/20160305154431/http://ada.org/1322.aspx|url-status=dead}}</ref>
[[Zinc pyrithione]] is widely included in shampoos to prevent dandruff.<ref>{{cite journal|journal=British Journal of Dermatology|volume=112|issue=4|pages=415–422|title=The effects of a shampoo containing zinc pyrithione on the control of dandruff|first=R.|last=Marks|author2=Pearse, A. D. |author3=Walker, A. P. |doi=10.1111/j.1365-2133.1985.tb02314.x|pmid=3158327|date=1985|s2cid=23368244}}</ref>
Topical zinc has also been shown to effectively treat, as well as prolong remission in [[genital herpes]].<ref>{{cite journal |last1=Mahajan |first1=BB |last2=Dhawan |first2=M |last3=Singh |first3=R |title=Herpes genitalis – Topical zinc sulfate: An alternative therapeutic and modality. |journal=Indian Journal of Sexually Transmitted Diseases and AIDS |date=January 2013 |volume=34 |issue=1 |pages=32–4 |doi=10.4103/0253-7184.112867 |pmid=23919052 |pmc=3730471 |doi-access=free }}</ref>
==Biological role==
{{Main|Zinc in biology}}
Zinc is an essential [[trace element]] for humans.<ref name="Maret-2013">{{cite book|first1= Wolfgang |last1= Maret|chapter= Zinc and Human Disease|editor=Astrid Sigel|editor2=Helmut Sigel|editor3=Roland K. O. Sigel|title=Interrelations between Essential Metal Ions and Human Diseases|series=Metal Ions in Life Sciences|volume=13|date=2013|publisher=Springer|pages=389–414|doi=10.1007/978-94-007-7500-8_12|pmid= 24470098|isbn= 978-94-007-7499-5}}</ref><ref name="Zinc - brain disorders 2015 review" /><ref name="Zinc & sleep 2017 review" /> and other animals,<ref name="Prasad-2008">{{cite journal|author=Prasad A. S.|title=Zinc in Human Health: Effect of Zinc on Immune Cells|journal=Mol. Med.|volume=14|date=2008|pmid=18385818|pmc=2277319|doi=10.2119/2008-00033.Prasad|issue=5–6|pages=353–7}}</ref> for plants<ref name="Broadley2007">{{cite journal|last=Broadley|first=M. R.|author2=White, P. J. |author3=Hammond, J. P. |author4=Zelko I. |author5= Lux A. |title=Zinc in plants|journal=New Phytologist|volume=173|date=2007|pmid=17286818|doi=10.1111/j.1469-8137.2007.01996.x|issue=4|pages=677–702|doi-access=free}}</ref> and for [[microorganism]]s.<ref name="Sugarman-1983">Zinc's role in microorganisms is particularly reviewed in: {{cite journal|author=Sugarman B|title=Zinc and infection|journal=Reviews of Infectious Diseases|volume=5|date=1983|pmid=6338570|issue=1|pages=137–47 |doi=10.1093/clinids/5.1.137}}</ref> Zinc is required for the function of over 300 [[enzyme]]s and 1000 [[transcription factor]]s,<ref name="Zinc & sleep 2017 review">{{cite journal | vauthors = Cherasse Y, Urade Y | title = Dietary Zinc Acts as a Sleep Modulator | journal = International Journal of Molecular Sciences | volume = 18 | issue = 11 | pages = 2334 | date = November 2017 | pmid = 29113075 | pmc = 5713303 | doi = 10.3390/ijms18112334 | quote = Zinc is the second most abundant trace metal in the human body, and is essential for many biological processes. &nbsp;... The trace metal zinc is an essential cofactor for more than 300 enzymes and 1000 transcription factors [16].&nbsp;... In the central nervous system, zinc is the second most abundant trace metal and is involved in many processes. In addition to its role in enzymatic activity, it also plays a major role in cell signaling and modulation of neuronal activity.| doi-access = free }}</ref> and is stored and transferred in [[metallothionein]]s.<ref name="Cotton1999bio">{{harvnb|Cotton et al.|1999|pp=625–629}}</ref><ref>{{Cite journal |last1=Plum|first1=Laura|last2=Rink |first2=Lothar|last3=Haase|first3=Hajo|title=The Essential Toxin: Impact of Zinc on Human Health|journal=Int J Environ Res Public Health|volume=7|issue=4|pages=1342–1365 |doi=10.3390/ijerph7041342|date=2010 |pmc=2872358 |pmid=20617034|doi-access=free}}</ref> It is the second most abundant trace metal in humans after iron and it is the only metal which appears in all [[Enzyme#Naming conventions|enzyme classes]].<ref name="Broadley2007" /><ref name="Zinc & sleep 2017 review" />
In proteins, zinc ions are often coordinated to the amino acid side chains of [[aspartic acid]], [[glutamic acid]], [[cysteine]] and [[histidine]]. The theoretical and computational description of this zinc binding in proteins (as well as that of other transition metals) is difficult.<ref>{{cite journal|title = Molecular dynamics study of zinc binding to cysteines in a peptide mimic of the alcohol dehydrogenase structural zinc site|journal = Phys. Chem. Chem. Phys. |volume = 11|issue = 6|pages = 975–83|date = 2009|pmid = 19177216|doi = 10.1039/b815482a|bibcode = 2009PCCP...11..975B|last1 = Brandt|first1 = Erik G.|last2 = Hellgren|first2 = Mikko|last3 = Brinck|first3 = Tore|last4 = Bergman|first4 = Tomas|last5 = Edholm|first5 = Olle|url = https://zenodo.org/record/996012}}</ref>
Roughly {{nowrap|2–4}}&nbsp;grams of zinc<ref name="Rink2000">{{cite journal|last=Rink|first =L.|author2=Gabriel P. |title=Zinc and the immune system|journal=Proc Nutr Soc|volume=59|date=2000|pmid=11115789|doi=10.1017/S0029665100000781|issue=4|pages=541–52|doi-access=free}}</ref> are distributed throughout the human body. Most zinc is in the brain, muscle, bones, kidney, and liver, with the highest concentrations in the prostate and parts of the eye.<ref>{{cite book|last=Wapnir|first=Raul A.|title=Protein Nutrition and Mineral Absorption|publisher=CRC Press|location=Boca Raton, Florida|date=1990|isbn=978-0-8493-5227-0|url=https://books.google.com/books?id=qfKdaCoZS18C}}</ref><!-- page 131 --> [[Semen]] is particularly rich in zinc, a key factor in [[prostate gland]] function and [[reproductive organ]] growth.<ref name="Berdanier2007">{{cite book|last=Berdanier|first=Carolyn D.|author2=Dwyer, Johanna T. |author3=Feldman, Elaine B. |title=Handbook of Nutrition and Food|publisher=CRC Press|location=Boca Raton, Florida|date=2007|isbn=978-0-8493-9218-4|url=https://books.google.com/books?id=PJpieIePsmUC}}</ref><!-- page 210 -->
Zinc homeostasis of the body is mainly controlled by the intestine. Here, [[SLC39A4|ZIP4]] and especially [[TRPM7]] were linked to intestinal zinc uptake essential for postnatal survival.<ref>{{Cite journal|last1=Mittermeier|first1=Lorenz|last2=Gudermann|first2=Thomas|last3=Zakharian|first3=Eleonora|last4=Simmons|first4=David G.|last5=Braun|first5=Vladimir|last6=Chubanov|first6=Masayuki|last7=Hilgendorff|first7=Anne|last8=Recordati|first8=Camilla|last9=Breit|first9=Andreas|date=February 15, 2019|title=TRPM7 is the central gatekeeper of intestinal mineral absorption essential for postnatal survival|journal=Proceedings of the National Academy of Sciences|volume=116|issue=10|pages=4706–4715|doi=10.1073/pnas.1810633116|issn=0027-8424|pmid=30770447|pmc=6410795|bibcode=2019PNAS..116.4706M |doi-access=free}}</ref><ref>{{Cite journal|last1=Kasana|first1=Shakhenabat|last2=Din|first2=Jamila|last3=Maret|first3=Wolfgang|date=January 2015|title=Genetic causes and gene–nutrient interactions in mammalian zinc deficiencies: acrodermatitis enteropathica and transient neonatal zinc deficiency as examples|journal=Journal of Trace Elements in Medicine and Biology|volume=29|pages=47–62|doi=10.1016/j.jtemb.2014.10.003|issn=1878-3252|pmid=25468189|bibcode=2015JTEMB..29...47K }}</ref>
In humans, the biological roles of zinc are ubiquitous.<ref name="Hambridge2007" /><ref name="Zinc - brain disorders 2015 review" /> It interacts with "a wide range of organic [[ligand]]s",<ref name="Hambridge2007" /> and has roles in the metabolism of RNA and DNA, [[signal transduction]], and [[gene expression]]. It also regulates [[apoptosis]]. A review from 2015 indicated that about 10% of human proteins (~3000) bind zinc,<ref name="pmid26055706">{{cite journal | vauthors = Djoko KY, Ong CL, Walker MJ, McEwan AG | title = The Role of Copper and Zinc Toxicity in Innate Immune Defense against Bacterial Pathogens | journal = The Journal of Biological Chemistry | volume = 290 | issue = 31 | pages = 18954–61 | date = July 2015 | pmid = 26055706 | pmc = 4521016 | doi = 10.1074/jbc.R115.647099 | quote = Zn is present in up to 10% of proteins in the human proteome and computational analysis predicted that ~30% of these ~3000 Zn-containing proteins are crucial cellular enzymes, such as hydrolases, ligases, transferases, oxidoreductases, and isomerases (42,43).| doi-access = free }}</ref> in addition to hundreds more that transport and traffic zinc; a similar ''[[in silico]]'' study in the plant ''[[Arabidopsis thaliana]]'' found 2367 zinc-related proteins.<ref name="Broadley2007" />
In the [[brain]], zinc is stored in specific [[synaptic vesicles]] by [[glutamatergic]] [[neuron]]s and can modulate neuronal excitability.<ref name="Zinc - brain disorders 2015 review" /><ref name="Zinc & sleep 2017 review" /><ref name="Bitanihirwe">{{cite journal | vauthors = Bitanihirwe BK, Cunningham MG | title = Zinc: the brain's dark horse | journal = Synapse | volume = 63 | issue = 11 | pages = 1029–1049 | date = November 2009 | pmid = 19623531 | doi = 10.1002/syn.20683 | s2cid = 206520330 }}</ref> It plays a key role in [[synaptic plasticity]] and so in learning.<ref name="Zinc - brain disorders 2015 review" /><ref>{{cite journal|author=Nakashima AS|author2=Dyck RH|date=2009|title=Zinc and cortical plasticity|journal=Brain Res Rev|volume=59|doi=10.1016/j.brainresrev.2008.10.003|pmid=19026685|issue=2|pages=347–73|s2cid=22507338}}</ref> Zinc [[homeostasis]] also plays a critical role in the functional regulation of the [[central nervous system]].<ref name="Zinc - brain disorders 2015 review" /><ref name="Bitanihirwe" /><ref name="Zinc & sleep 2017 review" /> Dysregulation of zinc homeostasis in the central nervous system that results in excessive synaptic zinc concentrations is believed to induce [[neurotoxicity]] through mitochondrial oxidative stress (e.g., by disrupting certain enzymes involved in the [[electron transport chain]], including [[complex I]], [[complex III]], and [[α-ketoglutarate dehydrogenase]]), the dysregulation of calcium homeostasis, glutamatergic neuronal [[excitotoxicity]], and interference with intraneuronal [[signal transduction]].<ref name="Zinc - brain disorders 2015 review" /><ref name="pmid25265815">{{cite journal | vauthors = Tyszka-Czochara M, Grzywacz A, Gdula-Argasińska J, Librowski T, Wiliński B, Opoka W | title = The role of zinc in the pathogenesis and treatment of central nervous system (CNS) diseases. Implications of zinc homeostasis for proper CNS function | journal = Acta Pol. Pharm. | volume = 71 | issue = 3 | pages = 369–377 | date = May 2014 | pmid = 25265815 | url = http://www.ptfarm.pl/pub/File/Acta_Poloniae/2014/3/369.pdf | url-status=live | archive-url = https://web.archive.org/web/20170829234531/http://www.ptfarm.pl/pub/File/Acta_Poloniae/2014/3/369.pdf | archive-date = August 29, 2017 | df = mdy-all }}</ref> L- and D-histidine facilitate brain zinc uptake.<ref>{{Cite journal |pmid=17119290|year=2006|last1=Yokel|first1=R. A.|title=Blood-brain barrier flux of aluminum, manganese, iron and other metals suspected to contribute to metal-induced neurodegeneration|journal=Journal of Alzheimer's Disease |volume=10|issue=2–3|pages=223–53|doi=10.3233/JAD-2006-102-309}}</ref> [[SLC30A3]] is the primary [[Solute carrier family#Solute carrier family 30|zinc transporter]] involved in cerebral zinc homeostasis.<ref name="Zinc - brain disorders 2015 review">{{cite journal | vauthors = Prakash A, Bharti K, Majeed AB | title = Zinc: indications in brain disorders | journal = Fundam Clin Pharmacol | volume = 29 | issue = 2 | pages = 131–149 | date = April 2015 | pmid = 25659970 | doi = 10.1111/fcp.12110| s2cid = 21141511 }}</ref>
===Enzymes===
[[File:Carbonic anhydrase.png|thumb|[[Ribbon diagram]] of human [[carbonic anhydrase]] II, with zinc atom visible in the center|alt=Interconnected stripes, mostly of yellow and blue color with a few red segments.]]
[[File:Zinc finger rendered.png|thumb|[[Zinc fingers]] help read DNA sequences.|alt=A twisted band, with one side painted blue and another gray. Its two ends are connected through some chemical species to a green atom (zinc).]]
Zinc is an efficient [[Lewis acid]], making it a useful catalytic agent in [[hydroxylation]] and other enzymatic reactions.<ref name="DRI" /> The metal also has a flexible [[coordination geometry]], which allows proteins using it to rapidly shift [[protein structure|conformations]] to perform biological reactions.<ref>{{cite book|last=Stipanuk|first=Martha H.|title=Biochemical, Physiological & Molecular Aspects of Human Nutrition|date=2006|pages=1043–1067|publisher=W. B. Saunders Company|isbn=978-0-7216-4452-3}}</ref> Two examples of zinc-containing enzymes are [[carbonic anhydrase]] and [[carboxypeptidase]], which are vital to the processes of [[carbon dioxide]] ({{chem|CO|2}}) regulation and digestion of proteins, respectively.<ref name="Greenwood1997p1224—1225">{{harvnb|Greenwood|Earnshaw|1997|pp=1224–1225}}</ref>
In vertebrate blood, carbonic anhydrase converts {{chem|CO|2}} into bicarbonate and the same enzyme transforms the bicarbonate back into {{chem|CO|2}} for exhalation through the lungs.<ref>{{cite book|last=Kohen|first=Amnon |author2=Limbach, Hans-Heinrich |title=Isotope Effects in Chemistry and Biology|publisher=CRC Press|location=Boca Raton, Florida|date=2006|page=850|isbn=978-0-8247-2449-8|url=https://books.google.com/books?id=7EiIqrRBBQgC}}</ref> Without this enzyme, this conversion would occur about one million times slower<ref name="Greenwood1997p1225">{{harvnb|Greenwood|Earnshaw|1997|p=1225}}</ref> at the normal blood [[pH]] of 7 or would require a pH of 10 or more.<ref name="Cotton1999p627">{{harvnb|Cotton et al.|1999|p=627}}</ref> The non-related β-carbonic anhydrase is required in plants for leaf formation, the synthesis of [[indole-3-acetic acid|indole acetic acid]] (auxin) and [[alcoholic fermentation]].<ref>{{cite journal|title=Effects of indole-3-acetic acid and zinc on the growth, osmotic potential and soluble carbon and nitrogen components of soybean plants growing under water deficit|last=Gadallah|first=MA |journal=Journal of Arid Environments|volume=44|date=2000|issue=4|pages=451–467|doi=10.1006/jare.1999.0610|bibcode=2000JArEn..44..451G}}</ref>
Carboxypeptidase cleaves peptide linkages during digestion of proteins. A [[coordinate covalent bond]] is formed between the terminal peptide and a C=O group attached to zinc, which gives the carbon a positive charge. This helps to create a [[hydrophobic]] pocket on the enzyme near the zinc, which attracts the non-polar part of the protein being digested.<ref name="Greenwood1997p1224—1225" />
===Signalling===
Zinc has been recognized as a messenger, able to activate signalling pathways. Many of these pathways provide the driving force in aberrant cancer growth. They can be targeted through [[Zinc transporter protein|ZIP transporters]].<ref>{{cite book|last1=Ziliotto|first1=Silvia| last2=Ogle |first2=Olivia| last3=Yaylor |first3=Kathryn M.|editor1-last=Sigel|editor1-first=Astrid|editor2-last=Sigel|editor2-first=Helmut|editor3-last=Freisinger|editor3-first=Eva|editor4-last=Sigel|editor4-first=Roland K. O.|title=Metallo-Drugs: Development and Action of Anticancer Agents|series=Metal Ions in Life Sciences|date=2018|volume= 18|doi= 10.1515/9783110470734-023 |pmid=29394036|publisher=de Gruyter GmbH|location=Berlin|chapter= Chapter 17. Targeting Zinc(II) Signalling to Prevent Cancer|pages= 507–529|isbn=9783110470734}}</ref>
===Other proteins===
Zinc serves a purely structural role in [[zinc finger]]s, twists and clusters.<ref name="Cotton1997p628">{{harvnb|Cotton et al.|1999|p=628}}</ref> Zinc fingers form parts of some [[transcription factor]]s, which are proteins that recognize [[DNA sequence|DNA base sequences]] during the replication and transcription of [[DNA]]. Each of the nine or ten {{chem|Zn|2+}} ions in a zinc finger helps maintain the finger's structure by coordinately binding to four [[amino acid]]s in the transcription factor.<ref name="Greenwood1997p1225" />
In [[blood plasma]], zinc is bound to and transported by [[albumin]] (60%, low-affinity) and [[transferrin]] (10%).<ref name="Rink2000" /> Because transferrin also transports iron, excessive iron reduces zinc absorption, and vice versa. A similar antagonism exists with copper.<ref name="Whitney2005">{{Cite book|first=Eleanor Noss|last=Whitney|author2=Rolfes, Sharon Rady |date=2005|title=Understanding Nutrition|pages=447–450|edition=10th|publisher=Thomson Learning|isbn=978-1-4288-1893-4}}</ref> The concentration of zinc in blood plasma stays relatively constant regardless of zinc intake.<ref name="DRI" /> Cells in the salivary gland, prostate, immune system, and intestine use [[Cell signaling|zinc signaling]] to communicate with other cells.<ref>{{Cite journal|last=Hershfinkel|first=M|author2=Silverman WF |author3=Sekler I |title=The Zinc Sensing Receptor, a Link Between Zinc and Cell Signaling |journal=Molecular Medicine|volume=13|date=2007|doi= 10.2119/2006-00038.Hershfinkel |pmid=17728842|issue=7–8|pmc=1952663|pages=331–336}}</ref>
Zinc may be held in [[metallothionein]] reserves within microorganisms or in the intestines or liver of animals.<ref name="Cotton1999p629">{{harvnb|Cotton et al.|1999|p=629}}</ref> Metallothionein in intestinal cells is capable of adjusting absorption of zinc by 15–40%.<ref name="Blake2007">{{Cite book|title=Vitamins and Minerals Demystified|last=Blake|first=Steve|publisher=McGraw-Hill Professional|date=2007|isbn=978-0-07-148901-0|page=242}}</ref> However, inadequate or excessive zinc intake can be harmful; excess zinc particularly impairs copper absorption because metallothionein absorbs both metals.<ref name="Fosmire1990" />
The human [[dopamine transporter]] contains a [[affinity (pharmacology)|high affinity]] extracellular zinc [[binding site]] which, upon zinc binding, inhibits dopamine [[reuptake]] and amplifies [[amphetamine]]-induced [[neurotransmitter efflux|dopamine efflux]] ''[[in vitro]]''.<ref name="Zinc binding sites + ADHD review">{{cite journal | vauthors = Krause J | title = SPECT and PET of the dopamine transporter in attention-deficit/hyperactivity disorder | journal = Expert Rev. Neurother. |volume = 8 |issue = 4 |pages = 611–625 |date = 2008 | pmid = 18416663 | doi = 10.1586/14737175.8.4.611| s2cid = 24589993 }}</ref><ref name="Review - cites 2002 amph-zinc primary study">{{cite journal | vauthors = Sulzer D | title = How addictive drugs disrupt presynaptic dopamine neurotransmission |journal = Neuron |volume = 69 |issue = 4 |pages = 628–649 | date =2011 |pmid = 21338876 |pmc = 3065181 |doi = 10.1016/j.neuron.2011.02.010}}</ref><ref name="Primary 2002 amph-zinc study">{{cite journal | vauthors = Scholze P, Nørregaard L, Singer EA, Freissmuth M, Gether U, Sitte HH | title = The role of zinc ions in reverse transport mediated by monoamine transporters | journal = J. Biol. Chem. | volume = 277 | issue = 24 | pages = 21505–21513 | date = 2002 | pmid = 11940571 | doi = 10.1074/jbc.M112265200 | quote = The human dopamine transporter (hDAT) contains an endogenous high affinity Zn<sup>2+</sup> binding site with three coordinating residues on its extracellular face (His193, His375, and Glu396).&nbsp;... Thus, when Zn<sup>2+</sup> is co-released with glutamate, it may greatly augment the efflux of dopamine.| doi-access = free }}</ref> The human [[serotonin transporter]] and [[norepinephrine transporter]] do not contain zinc binding sites.<ref name="Primary 2002 amph-zinc study" /> Some [[EF hand|EF-hand]] [[Calcium-binding protein|calcium binding proteins]] such as [[S100 protein|S100]] or [[Neuronal calcium sensor-1|NCS-1]] are also able to bind zinc ions.<ref>{{cite journal |last1=Tsvetkov |first1=PO |last2=Roman |first2=AY |last3=Baksheeva |first3=VE |last4=Nazipova |first4=AA |last5=Shevelyova |first5=MP |last6=Vladimirov |first6=VI |last7=Buyanova |first7=MF |last8=Zinchenko |first8=DV |last9=Zamyatnin AA |first9=Jr |last10=Devred |first10=F |last11=Golovin |first11=AV |last12=Permyakov |first12=SE |last13=Zernii |first13=EY |title=Functional Status of Neuronal Calcium Sensor-1 Is Modulated by Zinc Binding. |journal=Frontiers in Molecular Neuroscience |date=2018 |volume=11 |pages=459 |doi=10.3389/fnmol.2018.00459 |pmid=30618610|pmc=6302015 |doi-access=free }}</ref>
=== Nutrition ===
====Dietary recommendations====
The [[U.S. Institute of Medicine]] (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for zinc in 2001. The current EARs for zinc for women and men ages 14 and up is 6.8 and 9.4&nbsp;mg/day, respectively. The RDAs are 8 and 11&nbsp;mg/day. RDAs are higher than EARs so as to identify amounts that will cover people with higher than average requirements. RDA for pregnancy is 11&nbsp;mg/day. RDA for lactation is 12&nbsp;mg/day. For infants up to 12 months the RDA is 3&nbsp;mg/day. For children ages 1–13 years the RDA increases with age from 3 to 8&nbsp;mg/day. As for safety, the IOM sets [[Tolerable upper intake level]]s (ULs) for vitamins and minerals when evidence is sufficient. In the case of zinc the adult UL is 40&nbsp;mg/day including both food and supplements combined (lower for children). Collectively the EARs, RDAs, AIs and ULs are referred to as [[Dietary Reference Intake]]s (DRIs).<ref name="DRI">{{cite book |author=Institute of Medicine |year=2001 |chapter=Zinc |chapter-url=https://www.nap.edu/read/10026/chapter/14/ |doi=10.17226/10026 |pmid=25057538 |isbn=978-0-309-07279-3 |url-status=live |archive-url=https://web.archive.org/web/20170919234044/https://www.nap.edu/read/10026/chapter/14/ |archive-date=September 19, 2017 |pages=442–501 |title=Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc |location=Washington, DC |publisher=National Academy Press}}</ref>
The [[European Food Safety Authority]] (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in the United States. For people ages 18 and older the PRI calculations are complex, as the EFSA has set higher and higher values as the [[phytate]] content of the diet increases. For women, PRIs increase from 7.5 to 12.7&nbsp;mg/day as phytate intake increases from 300 to 1200&nbsp;mg/day; for men the range is 9.4 to 16.3&nbsp;mg/day. These PRIs are higher than the U.S. RDAs.<ref name="EFSA">{{cite web| title = Overview on Dietary Reference Values for the EU population as derived by the EFSA Panel on Dietetic Products, Nutrition and Allergies| year = 2017| url = https://www.efsa.europa.eu/sites/default/files/assets/DRV_Summary_tables_jan_17.pdf| url-status=live| archive-url = https://web.archive.org/web/20170828082247/https://www.efsa.europa.eu/sites/default/files/assets/DRV_Summary_tables_jan_17.pdf| archive-date = August 28, 2017| df = mdy-all}}</ref> The EFSA reviewed the same safety question and set its UL at 25&nbsp;mg/day, which is much lower than the U.S. value.<ref>{{citation| title = Tolerable Upper Intake Levels For Vitamins And Minerals| publisher = European Food Safety Authority| year = 2006| url = http://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf| url-status=live| archive-url = https://web.archive.org/web/20160316225123/http://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf| archive-date = March 16, 2016| df = mdy-all}}</ref>
For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For zinc labeling purposes 100% of the Daily Value was 15&nbsp;mg, but on May 27, 2016, it was revised to 11&nbsp;mg.<ref name="FedReg">{{cite web |url=https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf |title=Federal Register May 27, 2016 Food Labeling: Revision of the Nutrition and Supplement Facts Labels. FR page 33982. |url-status=live |archive-url=https://web.archive.org/web/20160808164651/https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf |archive-date=August 8, 2016 }}</ref><ref>{{cite web | title=Daily Value Reference of the Dietary Supplement Label Database (DSLD) | website=Dietary Supplement Label Database (DSLD) | url=https://www.dsld.nlm.nih.gov/dsld/dailyvalue.jsp | access-date=May 16, 2020 | archive-date=April 7, 2020 | archive-url=https://web.archive.org/web/20200407073956/https://dsld.nlm.nih.gov/dsld/dailyvalue.jsp | url-status=dead }}</ref> A table of the old and new adult daily values is provided at [[Reference Daily Intake]].
====Dietary intake====
[[File:Foodstuff-containing-Zinc.jpg|thumb|upright|[[Recommended Dietary Allowance|Foods and seasonings]] containing zinc|alt=Several plates full of various cereals, fruits and vegetables on a table.]]
Animal products such as meat, fish, shellfish, fowl, eggs, and dairy contain zinc. The concentration of zinc in plants varies with the level in the soil. With adequate zinc in the soil, the food plants that contain the most zinc are wheat (germ and bran) and various seeds, including [[sesame]], [[poppy]], [[alfalfa]], [[celery]], and [[Mustard (condiment)|mustard]].<ref name="Ensminger1993">{{Cite book|last=Ensminger|first=Audrey H.|author2=Konlande, James E. |title=Foods & Nutrition Encyclopedia|publisher=CRC Press|location=Boca Raton, Florida|date=1993|edition=2nd|pages=2368–2369|isbn=978-0-8493-8980-1|url=https://books.google.com/books?id=XMA9gYIj-C4C}}</ref> Zinc is also found in [[bean]]s, [[nut (fruit)|nuts]], [[almond]]s, [[whole grain]]s, [[pumpkin seed]]s, [[sunflower seed]]s, and [[blackcurrant]].<ref name="USDA_Zn">{{cite web|url=http://www.nal.usda.gov/fnic/foodcomp/Data/SR20/nutrlist/sr20w309.pdf |title=Zinc content of selected foods per common measure |access-date=December 6, 2007 |publisher=[[United States Department of Agriculture]] |work=USDA National Nutrient Database for Standard Reference, Release 20 |url-status=dead |archive-url=https://web.archive.org/web/20090305081926/http://www.nal.usda.gov/fnic/foodcomp/Data/SR20/nutrlist/sr20w309.pdf |archive-date=March 5, 2009 }}</ref>
Other sources include [[food fortification|fortified food]] and [[dietary supplement]]s in various forms. A 1998 review concluded that zinc oxide, one of the most common supplements in the United States, and zinc carbonate are nearly insoluble and poorly absorbed in the body.<ref name="Allen1998" /> This review cited studies that found lower plasma zinc concentrations in the subjects who consumed zinc oxide and zinc carbonate than in those who took zinc acetate and sulfate salts.<ref name="Allen1998">{{Cite journal|first=Lindsay H.|last=Allen|title=Zinc and micronutrient supplements for children|journal=American Journal of Clinical Nutrition|volume=68|issue=2 Suppl|date=1998|pmid=9701167|pages=495S–498S|doi=10.1093/ajcn/68.2.495S|doi-access=free}}</ref> For fortification, however, a 2003 review recommended cereals (containing zinc oxide) as a cheap, stable source that is as easily absorbed as the more expensive forms.<ref>{{Cite journal|last=Rosado|first=J. L.|title=Zinc and copper: proposed fortification levels and recommended zinc compounds|journal=Journal of Nutrition|volume=133|date=2003|pmid=12949397|issue=9|pages=2985S–9S|doi=10.1093/jn/133.9.2985S|doi-access=free}}</ref> A 2005 study found that various compounds of zinc, including oxide and sulfate, did not show statistically significant differences in absorption when added as fortificants to maize tortillas.<ref>{{cite journal|last=Hotz|first=C.|author2=DeHaene, J. |author3=Woodhouse, L. R. |author4=Villalpando, S. |author5=Rivera, J. A. |author6= King, J. C. |title=Zinc absorption from zinc oxide, zinc sulfate, zinc oxide + EDTA, or sodium-zinc EDTA does not differ when added as fortificants to maize tortillas|journal=Journal of Nutrition|volume=135|date=2005|pmid=15867288|issue=5|pages=1102–5|doi=10.1093/jn/135.5.1102|doi-access=free}}</ref>
===Deficiency===
{{Main|Zinc deficiency}}
Nearly two billion people in the developing world are deficient in zinc. Groups at risk include children in developing countries and elderly with chronic illnesses.<ref name="Prasad2003">{{cite journal|last=Prasad|first =AS|title=Zinc deficiency : Has been known of for 40 years but ignored by global health organisations|journal=British Medical Journal |volume=326 |date=2003|pmid=12595353|pmc=1125304|doi=10.1136/bmj.326.7386.409|issue=7386|pages=409–410}}</ref> In children, it causes an increase in infection and diarrhea and contributes to the death of about 800,000 children worldwide per year.<ref name="Hambridge2007" /> The World Health Organization advocates zinc supplementation for severe malnutrition and diarrhea.<ref name="WHO2007">{{cite web|title=The impact of zinc supplementation on childhood mortality and severe morbidity|publisher=World Health Organization |url=https://www.who.int/child_adolescent_health/documents/zinc_mortality/en/index.html|date=2007| archive-url=https://web.archive.org/web/20090302033104/http://www.who.int/child_adolescent_health/documents/zinc_mortality/en/index.html |archive-date=March 2, 2009}}</ref> Zinc supplements help prevent disease and reduce mortality, especially among children with low birth weight or stunted growth.<ref name="WHO2007" /> However, zinc supplements should not be administered alone, because many in the developing world have several deficiencies, and zinc interacts with other micronutrients.<ref>{{cite journal |last=Shrimpton |first=R|author2=Gross R |author3=Darnton-Hill I |author4= Young M |title=Zinc deficiency: what are the most appropriate interventions?|journal=British Medical Journal|volume=330|date=2005|pmid=15705693|pmc =548733|doi=10.1136/bmj.330.7487.347|issue=7487|pages=347–349}}</ref> While zinc deficiency is usually due to insufficient dietary intake, it can be associated with [[malabsorption]], [[acrodermatitis enteropathica]], chronic liver disease, chronic renal disease, [[sickle cell disease]], [[diabetes]], [[malignancy]], and other chronic illnesses.<ref name="Prasad2003" />
In the United States, a federal survey of food consumption determined that for women and men over the age of 19, average consumption was 9.7 and 14.2&nbsp;mg/day, respectively. For women, 17% consumed less than the EAR, for men 11%. The percentages below EAR increased with age.<ref>{{cite web|author1=Moshfegh, Alanna |author2=Goldman, Joseph |author3=Cleveland, Linda|date=2005|url=https://www.ars.usda.gov/SP2UserFiles/Place/80400530/pdf/0102/usualintaketables2001-02.pdf|access-date=January 6, 2015|title=NHANES 2001–2002: Usual Nutrient Intakes from Food Compared to Dietary Reference Intakes|publisher=U.S. Department of Agriculture, Agricultural Research Service|at=Table A13: Zinc}}</ref> The most recent published update of the survey (NHANES 2013–2014) reported lower averages – 9.3 and 13.2&nbsp;mg/day – again with intake decreasing with age.<ref>[https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/1314/Table_1_NIN_GEN_13.pdf What We Eat In America, NHANES 2013–2014] {{webarchive|url=https://web.archive.org/web/20170224042515/https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/1314/Table_1_NIN_GEN_13.pdf |date=February 24, 2017 }}.</ref>
Symptoms of mild zinc deficiency are diverse.<ref name="DRI" /> Clinical outcomes include depressed growth, diarrhea, impotence and delayed sexual maturation, [[alopecia]], eye and skin lesions, impaired appetite, altered cognition, impaired immune functions, defects in carbohydrate use, and reproductive [[teratogenesis]].<ref name="DRI" /> Zinc deficiency depresses immunity,<ref>{{cite journal|last=Ibs|first=KH|author2=Rink L|title=Zinc-altered immune function|journal=Journal of Nutrition |volume=133|issue=5 Suppl 1|date=2003|pmid=12730441|pages=1452S–1456S|doi=10.1093/jn/133.5.1452S|doi-access=free}}</ref> but excessive zinc does also.<ref name="Rink2000" />
Despite some concerns,<ref name="Canada 2003">{{cite journal|url=https://www.vrg.org/nutrition/2003_ADA_position_paper.pdf|pmid=12778049|year=2003|title=Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets|journal=Journal of the American Dietetic Association|volume=103|issue=6|pages=748–765 |doi=10.1053/jada.2003.50142|url-status=live|archive-url=https://web.archive.org/web/20170114103128/http://www.vrg.org/nutrition/2003_ADA_position_paper.pdf|archive-date=January 14, 2017|author1=American Dietetic Association}}</ref> western vegetarians and vegans do not suffer any more from overt zinc deficiency than meat-eaters.<ref>{{cite journal|author=Freeland-Graves JH|author2=Bodzy PW|author3=Epright MA|title=Zinc status of vegetarians|pmid=7440860|journal=Journal of the American Dietetic Association |date=1980 |volume=77|pages=655–661|issue=6|doi=10.1016/S1094-7159(21)03587-X|s2cid=8424197}}</ref> Major plant sources of zinc include cooked dried beans, sea vegetables, fortified cereals, soy foods, nuts, peas, and seeds.<ref name="Canada 2003" /> However, [[phytates]] in many whole-grains and fibers may interfere with zinc absorption and marginal zinc intake has poorly understood effects. The zinc [[chelation|chelator]] [[phytic acid|phytate]], found in seeds and [[cereal]] [[bran]], can contribute to zinc malabsorption.<ref name="Prasad2003" /> Some evidence suggests that more than the US RDA (8&nbsp;mg/day for adult women; 11&nbsp;mg/day for adult men) may be needed in those whose diet is high in phytates, such as some vegetarians.<ref name="Canada 2003" /> The [[European Food Safety Authority]] (EFSA) guidelines attempt to compensate for this by recommending higher zinc intake when dietary phytate intake is greater.<ref name="EFSA" /> These considerations must be balanced against the paucity of adequate zinc [[biomarker]]s, and the most widely used indicator, plasma zinc, has poor [[sensitivity and specificity]].<ref>{{cite journal|last=Hambidge|first=M|title=Biomarkers of trace mineral intake and status|journal=Journal of Nutrition|volume=133|series=133|date=2003|pmid=12612181|issue=3|pages=948S–955S|doi=10.1093/jn/133.3.948S|doi-access=free}}</ref>
===Soil remediation===
Species of ''[[Calluna]]'', ''[[Erica (plant)|Erica]]'' and ''[[Vaccinium]]'' can grow in zinc-metalliferous soils, because translocation of toxic ions is prevented by the action of [[Ericoid mycorrhiza|ericoid mycorrhizal fungi]].<ref>{{cite journal|url=http://mic.sgmjournals.org/content/156/3/609.full|title=Metals, minerals and microbes: geomicrobiology and bioremediation|journal=Microbiology|author1-link=Geoffrey Michael Gadd|author=Geoffrey Michael Gadd|volume=156|date=March 2010|pages=609–643|doi=10.1099/mic.0.037143-0|pmid=20019082|issue=3|url-status=live|archive-url=https://web.archive.org/web/20141025153753/http://mic.sgmjournals.org/content/156/3/609.full|archive-date=October 25, 2014|doi-access=free}}</ref>
===Agriculture===
Zinc deficiency appears to be the most common micronutrient deficiency in crop plants; it is particularly common in high-pH soils.<ref>{{cite web
|last1=Alloway
|first1=Brian J.
|title=Zinc in Soils and Crop Nutrition, International Fertilizer Industry Association, and International Zinc Association
|date=2008
|url=http://www.fertilizer.org/HomePage/LIBRARY/Our-selection2/Fertilizer-use.html/Zinc-in-Soils-and-Crop-Nutrition.html
|url-status=dead
|archive-url=https://web.archive.org/web/20130219203257/http://www.fertilizer.org/HomePage/LIBRARY/Our-selection2/Fertilizer-use.html/Zinc-in-Soils-and-Crop-Nutrition.html
|archive-date=February 19, 2013
}}</ref> Zinc-deficient [[soil]] is [[Tillage|cultivated]] in the cropland of about half of Turkey and India, a third of China, and most of Western Australia. Substantial responses to zinc fertilization have been reported in these areas.<ref name="Broadley2007" /> Plants that grow in soils that are zinc-deficient are more susceptible to disease. Zinc is added to the soil primarily through the weathering of rocks, but humans have added zinc through fossil fuel combustion, mine waste, phosphate fertilizers, pesticide ([[zinc phosphide]]), limestone, manure, sewage sludge, and particles from galvanized surfaces. Excess zinc is toxic to plants, although zinc toxicity is far less widespread.<ref name="Broadley2007" />
==Precautions==
{{main|Zinc toxicity}}
===Toxicity===
Although zinc is an essential requirement for good health, excess zinc can be harmful. Excessive absorption of zinc suppresses copper and iron absorption.<ref name="Fosmire1990" /> The free zinc ion in solution is highly toxic to plants, invertebrates, and even vertebrate fish.<ref>{{cite journal|journal=Contaminant Hazard Reviews |date=1993 |issue=10 |title=Zinc Hazard to Fish, Wildlife, and Invertebrates: A Synoptic Review |last=Eisler |first=Ronald |publisher=U.S. Department of the Interior, Fish and Wildlife Service |location=Laurel, Maryland |url=https://pubs.er.usgs.gov/publication/5200116 |url-status=live |archive-url=https://web.archive.org/web/20120306032807/http://www.pwrc.usgs.gov/infobase/eisler/chr_26_zinc.pdf |archive-date=March 6, 2012 }}</ref> The Free Ion Activity Model is well-established in the literature, and shows that just [[mole (unit)|micromolar]] amounts of the free ion kills some organisms. A recent example showed 6 micromolar killing 93% of all ''[[Daphnia]]'' in water.<ref>{{cite journal|title=Mechanisms of chronic waterborne Zn toxicity in Daphnia magna|first1=Brita T. A.|last1=Muyssen|last2=De Schamphelaere|first2=Karel A. C.|last3=Janssen|first3=Colin R.|journal=Aquatic Toxicology|volume=77|issue=4|date=2006|pmid=16472524|doi=10.1016/j.aquatox.2006.01.006|pages=393–401|bibcode=2006AqTox..77..393M }}</ref>
The free zinc ion is a powerful [[Lewis acid]] up to the point of being [[corrosive]]. Stomach acid contains [[hydrochloric acid]], in which metallic zinc dissolves readily to give corrosive zinc chloride. Swallowing a post-1982 American one [[Cent (United States coin)|cent]] piece (97.5% zinc) can cause damage to the stomach lining through the high solubility of the zinc ion in the acidic stomach.<ref>{{cite journal|title=Chronic Ingestion of a Zinc-Based Penny|first=Dawn N.|last=Bothwell|author2=Mair, Eric A. |author3=Cable, Benjamin B. |journal=Pediatrics|volume=111|date=2003|doi=10.1542/peds.111.3.689|pmid=12612262|issue=3|pages=689–91}}</ref>
Evidence shows that people taking 100–300&nbsp;mg of zinc daily may suffer induced [[copper deficiency]]. A 2007 trial observed that elderly men taking 80&nbsp;mg daily were hospitalized for urinary complications more often than those taking a placebo.<ref>{{cite journal|author=Johnson AR|author2=Munoz A|author3=Gottlieb JL|author4=Jarrard DF|title=High dose zinc increases hospital admissions due to genitourinary complications|journal=J. Urol.|volume=177|date=2007|pmid=17222649|doi=10.1016/j.juro.2006.09.047|issue=2|pages=639–43}}</ref> Levels of 100–300&nbsp;mg may interfere with the use of copper and iron or adversely affect cholesterol.<ref name="Fosmire1990">{{cite journal|journal=American Journal of Clinical Nutrition|volume=51|date=1990|title=Zinc toxicity|first=G. J.|last=Fosmire|pmid=2407097|issue=2|pages=225–7|doi=10.1093/ajcn/51.2.225}}</ref> Zinc in excess of 500&nbsp;ppm in soil interferes with the plant absorption of other essential metals, such as iron and manganese.<ref name="Emsley2001p504" /> A condition called the [[zinc shakes]] or "zinc chills" can be induced by inhalation of zinc fumes while [[brazing]] or welding galvanized materials.<ref name="CRCp4-42" /> Zinc is a common ingredient of [[denture]] cream which may contain between 17 and 38&nbsp;mg of zinc per gram. Disability and even deaths from excessive use of these products have been claimed.<ref>{{Cite news |url=http://www.tampabay.com/news/health/lawsuits-blame-denture-adhesives-for-neurological-damage/1073320 |title=Lawsuits blame denture adhesives for neurological damage (Denture adhesives cited in lawsuits) |newspaper=[[Tampa Bay Times|St. Petersburg Times]] |author=Richard Martin |date=February 15, 2010 |access-date=December 31, 2022 |archive-url=https://web.archive.org/web/20121011122902/https://www.tampabay.com/news/health/lawsuits-blame-denture-adhesives-for-neurological-damage/1073320/ |archive-date=October 11, 2012 |url-status=dead}}</ref>
The U.S. [[Food and Drug Administration]] (FDA) states that zinc damages nerve receptors in the nose, causing [[anosmia]]. Reports of anosmia were also observed in the 1930s when zinc preparations were used in a failed attempt to prevent [[polio]] infections.<ref>{{Cite book|url=https://books.google.com/books?id=n24Pju7kHIYC&pg=PA142|page=142|title=Conquest of viral diseases: a topical review of drugs and vaccines|author=Oxford, J. S.|author2=Öberg, Bo|publisher=Elsevier|date=1985|isbn=978-0-444-80566-9}}</ref> On June 16, 2009, the FDA ordered removal of zinc-based intranasal cold products from store shelves. The FDA said the loss of smell can be life-threatening because people with impaired smell cannot detect leaking gas or smoke, and cannot tell if food has spoiled before they eat it.<ref name="LAT">{{cite news|url=https://www.latimes.com/archives/la-xpm-2009-jun-17-sci-zicam17-story.html|title=FDA says Zicam nasal products harm sense of smell|newspaper=Los Angeles Times|date=June 17, 2009|url-status=live|archive-url=https://web.archive.org/web/20120621011505/http://articles.latimes.com/2009/jun/17/science/sci-zicam17|archive-date=June 21, 2012}}</ref>
Recent research suggests that the topical antimicrobial zinc pyrithione is a potent [[heat shock]] response inducer that may impair genomic integrity with induction of [[Poly ADP ribose polymerase|PARP]]-dependent energy crisis in cultured human [[keratinocyte]]s and [[melanocyte]]s.<ref>{{cite journal |author=Lamore SD |author2=Cabello CM |author3=Wondrak GT |title=The topical antimicrobial zinc pyrithione is a heat shock response inducer that causes DNA damage and PARP-dependent energy crisis in human skin cells |journal=Cell Stress & Chaperones |volume=15 |issue=3 |pages=309–22 |date=2010 |pmid=19809895 |doi=10.1007/s12192-009-0145-6 |pmc=2866994 }}</ref>
===Poisoning===
In 1982, the [[United States Mint|US Mint]] began minting [[Cent (United States coin)|pennies]] coated in copper but containing primarily zinc. Zinc pennies pose a risk of zinc toxicosis, which can be fatal. One reported case of chronic ingestion of 425 pennies (over 1&nbsp;kg of zinc) resulted in death due to gastrointestinal bacterial and fungal [[sepsis]]. Another patient who ingested 12&nbsp;grams of zinc showed only [[lethargy]] and [[ataxia]] (gross lack of coordination of muscle movements).<ref>{{cite journal
|title=Zinc|first=Donald G.|last=Barceloux|journal=Clinical Toxicology|author2=Barceloux, Donald |volume=37
|issue=2|pages=279–292|date=1999|doi =10.1081/CLT-100102426|pmid=10382562}}</ref> Several other cases have been reported of humans suffering zinc intoxication by the ingestion of zinc coins.<ref>{{cite journal|title=Zinc Toxicity Following Massive Coin Ingestion|journal=American Journal of Forensic Medicine and Pathology|volume=18|issue=2|pages=148–153|date=1997|last=Bennett|first=Daniel R. M. D.|author2=Baird, Curtis J. M.D. |author3=Chan, Kwok-Ming |author4=Crookes, Peter F. |author5=Bremner, Cedric G. |author6=Gottlieb, Michael M. |author7= Naritoku, Wesley Y. M.D. |doi=10.1097/00000433-199706000-00008|pmid=9185931}}</ref><ref>{{cite journal|journal=Radiology|volume=158|page=512|date=1986|title=Coin ingestion: unusual appearance of the penny in a child|first=S. K.|last=Fernbach|author2=Tucker G. F. |pmid=3941880|issue=2|doi=10.1148/radiology.158.2.3941880}}</ref>
Pennies and other small coins are sometimes ingested by dogs, requiring veterinary removal of the foreign objects. The zinc content of some coins can cause zinc toxicity, commonly fatal in dogs through severe [[hemolytic anemia]] and liver or kidney damage; vomiting and diarrhea are possible symptoms.<ref>{{cite journal|title=Zinc phosphide poisoning in dogs|journal=Journal of the American Veterinary Medical Association|volume=173|page=270|date=1978|pmid=689968|issue=3|last1=Stowe|first1=C. M.|last2=Nelson|first2=R.|last3=Werdin|first3=R.|last4=Fangmann|first4=G.|last5=Fredrick|first5=P.|last6=Weaver|first6=G.|last7=Arendt|first7=T. D.}}</ref> Zinc is highly toxic in [[parrots]] and poisoning can often be fatal.<ref>{{cite journal|journal =Australian Veterinary Journal|volume=63|issue =6|page=199|title=Zinc toxicity (new wire disease) in aviary birds|first=R. L.|last=Reece|author2=Dickson, D. B. |author3=Burrowes, P. J. |doi=10.1111/j.1751-0813.1986.tb02979.x|pmid=3767804|date =1986}}</ref> The consumption of fruit juices stored in galvanized cans has resulted in mass parrot poisonings with zinc.<ref name="Emsley2001p501" />
==See also==
* [[List of countries by zinc production]]
* [[Spelter]]
* [[Wet storage stain]]
* [[Zinc alloy electroplating]]
* [[Metal fume fever]]
* [[Piotr Steinkeller]]
== Notes ==
{{notelist}}
== References==
{{reflist}}
=== Bibliography ===
<!-- NOTE: Only list multipage works here that are cited to different pages in the prose -->
{{refbegin}}
* <!-- Ch -->{{cite book
|title=Chambers's Encyclopaedia: A Dictionary of Universal Knowledge
|year=1901
|last=Chambers
|first=William and Robert
|edition=Revised
|location=London and Edinburgh
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|url=https://books.google.com/books?id=Rz8oAAAAYAAJ
}}
* <!-- Co -->{{cite book
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|author2=Wilkinson, Geoffrey |author3=Murillo, Carlos A. |author4= Bochmann, Manfred
|title=Advanced Inorganic Chemistry
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}}
* <!-- CRC -->{{cite book
|title=Handbook of Chemistry and Physics
|editor=David R. Lide
|edition=87th
|year=2006
|url=https://books.google.com/books?id=WDll8hA006AC&pg=PT893
|publisher=CRC Press, Taylor & Francis Group
|location=Boca Raton, Florida
|isbn=978-0-8493-0487-3
|ref=CITEREFCRC2006}}
* <!-- Em -->{{cite book
|title=Nature's Building Blocks: An A-Z Guide to the Elements
|last=Emsley
|first=John
|publisher=Oxford University Press
|year=2001
|location=Oxford, England, UK
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|chapter=Zinc
|pages=[https://archive.org/details/naturesbuildingb0000emsl/page/499 499–505]
|chapter-url=https://books.google.com/books?id=j-Xu07p3cKwC
|url=https://archive.org/details/naturesbuildingb0000emsl/page/499
}}
* <!-- Gr -->{{cite book
|last1=Greenwood
|first1=N. N.
|last2=Earnshaw |first2=A.
|title=Chemistry of the Elements
|edition=2nd
|publisher=Butterworth-Heinemann
|location=Oxford
|year=1997
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}}
* <!-- He -->{{cite book
|last=Heiserman
|first=David L.
|title=Exploring Chemical Elements and their Compounds
|location=New York
|publisher=TAB Books
|isbn=978-0-8306-3018-9
|chapter=Element 30: Zinc
|chapter-url=https://books.google.com/books?id=24l-Cpal9oIC
|year=1992
|url=https://archive.org/details/exploringchemica01heis
}}
* <!-- Le -->{{cite book
|title=The Encyclopedia of the Chemical Elements
|chapter-url=https://archive.org/details/encyclopediaofch00hamp
|chapter-url-access=registration
|publisher=Reinhold Book Corporation
|location=New York
|year=1968
|editor=Clifford A. Hampel
|last=Lehto
|first=R. S.
|isbn=978-0-442-15598-8
|chapter=Zinc
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|lccn=68-29938
}}
* <!-- Sw -->{{cite book
|title=Guide to the Elements
|chapter-url=https://archive.org/details/guidetoelements00stwe
|chapter-url-access=registration
|edition=Revised
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|chapter=Zinc
|isbn=978-0-19-508083-4
}}
* <!-- We -->{{cite book
|last=Weeks
|first=Mary Elvira
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|title=The Discovery of the Elements
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|location=Easton, PA
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|isbn=978-0-7661-3872-8
}}
{{refend}}
==External links==
{{Spoken Wikipedia|Zinc spoken.ogg|date=January 25, 2012}}
{{Commons|Zinc}}
{{Wiktionary|zinc}}
* [http://ods.od.nih.gov/factsheets/zinc/ Zinc Fact Sheet] from the U.S. [[National Institutes of Health]]
* [http://elements.vanderkrogt.net/element.php?sym=Zn History & Etymology of Zinc]
* [http://minerals.usgs.gov/minerals/pubs/commodity/zinc/index.html Statistics and Information from the U.S. Geological Survey]
* [https://www.organic-chemistry.org/chemicals/reductions/zinc-zn.shtm Reducing Agents > Zinc]
* [http://www.zinc.org American Zinc Association] Information about the uses and properties of zinc.
* [http://www.iszb.org ISZB] International Society for Zinc Biology, founded in 2008. An international, nonprofit organization bringing together scientists working on the biological actions of zinc.
* [http://zinc-uk.org Zinc-UK] Founded in 2010 to bring together scientists in the United Kingdom working on zinc.
* [http://www.periodicvideos.com/videos/030.htm Zinc] at ''[[The Periodic Table of Videos]]'' (University of Nottingham)
* [https://zincbind.net ZincBind] – a database of biological zinc binding sites.
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