Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc 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 (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 Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity (electrowinning).

Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It is the second most abundant trace metal in humans after iron and it is the only metal which appears in all enzyme classes. Zinc is also an essential nutrient element for coral growth as it is an important cofactor for many enzymes. Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, and diarrhea. Enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. 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. Brass, an alloy of copper and zinc in various proportions, was used as early as the third millennium BC in the Aegean area and the region which currently includes Iraq, the United Arab Emirates, Kalmykia, Turkmenistan and Georgia. In the second millennium BC it was used in the regions currently including West India, Uzbekistan, Iran, Syria, Iraq, and Israel. 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. The mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, 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. 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 zinc plating of iron (hot-dip galvanizing) is the major application for zinc. Other applications are in electrical 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.

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Atomic properties

Standard atomic weight65.38 ±0.02
Atomic mass65.382 u

Atomic radii

Radius (empirical)134 pm
Radius (calculated)142 pm
Covalent radius122 ±4 pm
Van der Waals radius139 pm

Atomic shell

Electron configurationAr 3d10 4s2
Ionization energy(1st) 9.394197 eV
(2nd) 17.96439 eV
(3rd) 39.7233 eV
(4th) 59.573 eV
(5th) 82.6 eV
Shell model

Physical properties

Density7.14 g·cm−3 (298.1 K)
Molar volume9.16·10-6 m3·mol−1
Speed of sound3,700 m·s−1


Melting point692.6 K
Boiling point1,180 K
Liquid range487.3 K
Transition temperature0.85 K


Melting enthalpy7.35 kJ·mol-1
Enthalpy of vaporization119 kJ·mol-1
Binding energy131 kJ·mol-1

Heat and conductivity

Specific heat capacity388 J·kg−1·K−1
Thermal conductivity120 W·m-1·K-1
Expansion coefficient3.02·10-5 K-1


Mohs hardness2.5
Brinell hardness412 NM·m-2

Elastic properties

Young’s modulus108 GPa
Shear modulus43 GPa
Bulk modulus70 GPa
Poisson’s ratio0.25

Electrical properties

Electrical conductivity1.67·107 S·m-1
Resistance5.999·10-8 Ωm


Magnetic susceptibility-1.141·10-5 cm3·mol−1 (298 K)

Optical properties

Reflectivity80 %
Refractive index1.002

Chemical properties

Oxidation state2
Standard potential-0.7926 V (Zn2+ + 2e- → Zn)


Pauling scale1.65
Sanderson scale2.23
Allred-Rochow scale1.66
Mulliken scale1.65
Ghosh-Gupta scale4.133 eV
Nagle scale1.46
Pearson absolute negativity4.45 eV

Other properties

Natural occurrenceprimordial
Crystal structureHexagonal close-packed
Goldschmidt Classificationchalcophile
Superconductorwith transition tempperature (solid body, normal pressure)
Price/kg2.55 USD

Natural abundances

300 ppb ≈ 3.01·1012 M☉
2,000 ppb ≈ 3.97·1012 Mt
180,000 ppb ≈ 180 g
Earth’s crust
79,000 ppb ≈ 2.18·106 Mt
5 ppb ≈ 6.85 Gt
Flowing water
10 ppb ≈ 160 kt
Human body
33,000 ppb ≈ 2.31 g