Zinc

This article is about the chemical element. For other uses, see Zinc (disambiguation).

Zinc is a chemical element with the 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 (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.^[b] 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, ₃₀Zn

Zinc
Appearance	silver-gray
Standard atomic weight Ar°(Zn)
	65.38±0.02[1] 65.38±0.02 (abridged)[2]
Zinc in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson – ↑ Zn ↓ Cd copper ← zinc → gallium
Atomic number (Z)	30
Group	group 12
Period	period 4
Block	d-block
Electron configuration	[Ar] 3d10 4s2
Electrons per shell	2, 8, 18, 2
Physical properties
Phase at STP	solid
Melting point	692.68 K ​(419.53 °C, ​787.15 °F)
Boiling point	1180 K ​(907 °C, ​1665 °F)
Density (at 20° C)	7.140 g/cm3 [3]
when liquid (at m.p.)	6.57 g/cm3
Heat of fusion	7.32 kJ/mol
Heat of vaporization	115 kJ/mol
Molar heat capacity	25.470 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 610 670 750 852 990 1179
Atomic properties
Oxidation states	common: +2 −2,[4] 0,? +1[5]
Electronegativity	Pauling scale: 1.65
Ionization energies	1st: 906.4 kJ/mol 2nd: 1733.3 kJ/mol 3rd: 3833 kJ/mol (more)
Atomic radius	empirical: 134 pm
Covalent radius	122±4 pm
Van der Waals radius	139 pm
Spectral lines of zinc
Other properties
Natural occurrence	primordial
Crystal structure	​hexagonal close-packed (hcp) (hP2)
Lattice constants	a = 266.46 pm c = 494.55 pm (at 20 °C)[3]
Thermal expansion	30.08×10−6/K (at 20 °C)[a]
Thermal conductivity	116 W/(m⋅K)
Electrical resistivity	59.0 nΩ⋅m (at 20 °C)
Magnetic ordering	diamagnetic
Molar magnetic susceptibility	−11.4×10−6 cm3/mol (298 K)[6]
Young's modulus	108 GPa
Shear modulus	43 GPa
Bulk modulus	70 GPa
Speed of sound thin rod	3850 m/s (at r.t.) (rolled)
Poisson ratio	0.25
Mohs hardness	2.5
Brinell hardness	327–412 MPa
CAS Number	7440-66-6
History
Discovery	Indian metallurgists (before 1000 BCE)
First isolation	Andreas Sigismund Marggraf (1746)
Recognized as a unique metal by	Rasaratna Samuccaya (1300)
Isotopes of zinc