General
Name Zinc Symbol Zn
atomic number 30 Atomic weight 65.38
Density @ 293 K 7.14 g/cm3 Atomic volume 9.2 cm3/mol
Group Trans. Met. discovered 1600
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States
state (s, l, g) s
melting point 692.78 K boiling point 1180 K
Heat of fusion 7.322 kJ/mol Heat of vaporization 115.30 kJ/mol

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Energies
1st ionization energy 906.4 kJ/mole electronegativity 1.65
2nd ionization energy 1733.2 kJ/mole electron affinity kJ/mole
3rd ionization energy 3832.6 kJ/mole Specific heat 0.39 J/gK
heat atomization 131 kJ/mole atoms
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Oxidation & Electrons
Shells 2,8,18,2 electron configuration [Ar] 3d10 4s2
minimum oxidation number 0 maximum oxidation number 2
min. common oxidation no. 0 max. common oxidation no. 2

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Appearance & Characteristics
structure distorted hcp structure color silvery
uses batteries, galvanizing toxicity
hardness 2.5 mohs characteristics brittle
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Reactions
reaction with air vigorous, =>ZnO reaction with 6M HCl mild, =>H2, ZnCl2
reaction with 6M HCl mild, =>H2, ZnCl2 reaction with 15M HNO3 vigorous, =>Zn(NO3)2, NOx
reaction with 6M NaOH mild, =>[Zn(OH)4](2-), H2

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Other Forms
number of isotopes 5 hydride(s) ZnH2
oxide(s) ZnO chloride(s) ZnCl2
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Radius
ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 134 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) 88 pm ionic radius (3+ ion) pm

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Conductivity
thermal conductivity 116 J/m-sec-deg electrical conductivity 169.033 1/mohm-cm
polarizability 6.4 A^3
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Abundance
source Sphalerite (sulfide) rel. abund. solar system 3.100 log
abundance earth's crust 1.79 log cost, pure 3.7 $/100g
cost, bulk 0.12 $/100g

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History:

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(Ger. Zink, of obscure origin) Centuries before zinc was recognized as a distinct element, zinc ores were used for making brass. Tubal-Cain, seven generations from Adam, is mentioned as being an "instructor in every artificer in brass and iron." An alloy containing 87% zinc has been found in prehistoric ruins in Transylvania. Metallic zinc was produced in the 13th century A.D. in India by reducing calamine with organic substances such as wool. The metal was rediscovered in Europe by Marggraf in 1746, who showed that it could be obtained by reducing calamine with charcoal. The principal ores of zinc are sphalerite (sulfide), smithsonite (carbonate), calamine (silicate), and franklinite (zine, manganese, iron oxide). Zinc can be obtained by roasting its ores to form the oxide and by reduction of the oxide with coal or carbon, with subsequent distillation of the metal. Other methods of extraction are possible. Naturally occurring zinc contains five stable isotopes. Sixteen other unstable isotopes are recognized. Zinc is a bluish-white, lustrous metal. It is brittle at ordinary temperatures but malleable at 100 to 150C. It is a fair conductor of electricity, and burns in air at high red heat with evolution of white clouds of the oxide. The metal is employed to form numerous alloys with other metals. Brass, nickel silver, typewriter metal, commercial bronze, spring bronze, German silver, soft solder, and aluminum solder are some of the more important alloys. Large quantities of zinc are used to produce die castings, used extensively by the automotive, electrical, and hardware industries. An alloy called Prestal(R), consisting of 78% zinc and 22% aluminum is reported to be almost as strong as steel but as easy to mold as plastic. It is said to be so plastic that it can be molded into form by relatively inexpensive die casts made of ceramics and cement. It exhibits superplasticity. Zinc is also used extensively to galvanize other metals such as iron to prevent corrosion. Neither zinc nor zirconium is ferromagnetic; but ZrZn2 exhibits ferromagnetism at temperatures below 35 K. Zinc oxide is a unique and very useful material to modern civilization. It is widely used in the manufacture of paints, rubber products, cosmetics, pharmaceuticals, floor coverings, plastics, printing inks, soap, storage batteries, textiles, electrical equipment, and other products. It has unusual electrical, thermal, optical, and solid-state properties that have not been fully investigated. Lithopone, a mixture of zinc sulfide and barium sulfate, is an important pigment. Zinc sulfide is used in making luminous dials, X-ray and TV screens, and fluorescent lights. The chloride and chromate are also important compounds. Zinc is an essential element in the growth of human beings and animals. Tests show that zinc-deficient animals require 50% more food to gain the same weight as an animal supplied with sufficient zinc. Zinc is not considered to be toxic, but when freshly formed ZnO is inhaled a disorder known as the oxide shakes or zinc chills sometimes occurs. It is recommended that where zinc oxide is encountered good ventilation be provided to avoid concentration exceeding 5 mg/m^3, (time-weighted over an 8-hour exposure, 40-hour work week). The price of zinc was roughly $0.70/lb in January 1990.