Nickel

Cobalt - Nickel - Copper Ni Pd       Full table
General
Name, Symbol, Number	Nickel, Ni, 28
Chemical series	Transition metals
Group, Period, Block	10 [?], 4 , d
Density, Hardness	8908 kg/m3, 4.0
Appearance	lustrous, metallic, silvery tinge
Atomic Properties
Atomic weight	58.6934 amu
Atomic radius (calc.)	135 (149) pm
Covalent radius	121 pm
van der Waals radius	163 pm
Electron configuration	[Ar]3d84s2
e- 's per energy level	2, 8, 16, 2
Oxidation states (Oxide)	2,3 (mildly basic)
Crystal structure	Cubic, face-centered
Physical Properties
State of matter	solid (ferromagnetic)
Melting point	1728 K (2651 °F)
Boiling point	3186 K (5275 °F)
Molar volume	6.59 ×10-3 m3/mol
Heat of vaporization	370.4 kJ/mol
Heat of fusion	17.47 kJ/mol
Vapor pressure	237 Pa at 1726 K
Velocity of sound	4970 m/s at 293.15 K
Miscellaneous
Electronegativity	1.91 (Pauling scale)
Specific heat capacity	440 J/(kg*K)
Electrical conductivity	14.3 106/m ohm
Thermal conductivity	90.7 W/(m*K)
1st ionization potential	737.1 kJ/mol
2nd ionization potential	1753 kJ/mol
3rd ionization potential	3395 kJ/mol
4th ionization potential	5300 kJ/mol
Most Stable Isotopes
iso NA half-life DM DE MeV DP 56Ni {syn.} 6.077 days e capture 2.136 56Co 58Ni 68.077% Ni is stable with 30 neutrons 59Ni {syn.} 76000 years e capture 1.072 59Co 60Ni 26.233% Ni is stable with 32 neutrons 61Ni 1.14% Ni is stable with 33 neutrons 62Ni 3.634% Ni is stable with 34 neutrons 63Ni {syn.} 100.1 years β- 2.137 63Cu 64Ni 0.926% Ni is stable with 36 neutrons
SI units & STP are used except where noted.

Nickel is a chemical element in the periodic table that has the symbol Ni and atomic number 28.

Table of contents 1 Notable Characteristics 2 Applications 3 History 4 Biological Role 5 Occurrence 6 Compounds 7 Isotopes 8 Precautions 9 External Links

Notable Characteristics Nickel is silvery white metal that takes on a high polish. It is of the iron group, and is hard, malleable, and ductile. It occurs combined with sulphur in millerite, with arsenic in the mineral niccolite, and with arsenic and sulphur in nickel glance.

On account of its permanence in air and inertness to oxidation, it is used in the smaller coins, for plating iron, brass, etc., for chemical apparatus, and in certain alloys, as german silver. It is magnetic, and is very frequently accompanied by cobalt, both being found in meteoric iron. It is chiefly valuable for the alloys it forms.

The most common oxidation_state of nickel is +2, though rarely, +1 and +3 Ni complexes are observed. Applications About 65% of the nickel consumed in the Western World is used to make austenitic stainless steel. Another 12% goes into superalloys. The remaining 23% of consumption is divided between alloy steels, rechargeable batteries, catalysts and other chemicals, coinage, foundry products, and plating.

Applications include:

• Stainless steel and other corrosion-resistant alloys.
• Nickel steel[?] is used for armor plates and burglar-proof vaults.
• The alloy Alnico[?] is used in magnets.
• Mu-metal has an especially high magnetic permeability, and is used to screen magnetic fields.
• Smart wire, or shape memory alloys, are used in robotics.
• Rechargable batteries, such as nickel metal hydride batteries and nickel cadmium batteries.
• Coinage.
• In electroplating.
• In crucibles for chemical laboratories.
• Finely divided nickel is a catalyst for hydrogenating vegetable oils.

History Nickel use is ancient, and can be traced back as far as 3500 BC. Bronzes from what is now Syria had a nickel content of up to two percent. Further, there are Chinese manuscripts suggesting that "white copper" (e.g. paitung) was used in the Orient between 1400 and 1700 BC. However, because the ores of nickel were easily mistaken for ores of silver, any understanding of this metal and its use dates to more contemporary times.

Minerals containing nickel (e.g. kupfernickel, or false copper) were of value for coloring glass green. In 1751, Baron Axel Frederik Cronstedt was attempting to extract copper from kupfernickel (now called niccolite), and obtained instead a white metal that he called nickel.

The first nickel coin of the pure metal was made in 1881.

Biological Role Many but not all hydrogenases[?] contain nickel in addition to iron-sulfur clusters. Nickel centers are a common element in those hydrogenases whose function is to oxidize rather than evolve hydrogen. The nickel center appears to undergo changes in oxidation state, and evidence has been presented that the nickel center might be the active site of these enzymes.

A nickel-tetrapyrrole coenzyme, Co-F430, is present in the methyl CoM reductase and in methanogenic[?] bacteria. The tetrapyrrole is intermediate in structure between porphyrin and corrin. Changes in redox state, as well as changes in nickel coordination, have recently been observed.

There is also a nickel-containing carbon monoxide dehydrogenase. Little is known about the structure of the nickel site.

Occurrence The bulk of the nickel mined comes from two types of ore deposits. The first are laterites where the principal ore minerals are nickeliferous limonite [(Fe,Ni)O(OH)] and garnierite (a hydrous nickel silicate). The second are magmatic sulfide deposits where the principal ore mineral is pentlandite [(Ni,Fe)₉S₈].

In terms of supply, the Sudbury region of Ontario, Canada, produces about 30 percent of the world's supply of nickel. Other deposits are found in Russia, New Caledonia, Australia, Cuba, and Indonesia. However, most of the nickel on Earth is believed to be concentrated in the planet's core.

Compounds Kamacite

Isotopes Naturally occurring nickel is composed of 5 stable isotopes; 58-Ni, 60-Ni, 61-Ni, 62-Ni and 64-Ni with 58-Ni being the most abundant (68.077% natural abundance). 18 radioisotopes have been characterized with the most stable being 59-Ni with a half-life of 76,000 years, 63-Ni with a half-life of 100.1 years, and 56-Ni with a half-life of 6.077 days. All of the remaining radioactive isotopes have half-lifes that are less than 60 hours and the majority of these have half lifes that are less than 30 seconds. This element also has 1 meta state.

Nickel-56 is produced in large quantities in type II supernova[?] and the shape of the light curve of these supernova corresponds to the decay of nickel-56 to cobalt-56 and then to iron-56.

Nickel-59 is a long-lived cosmogenic radionuclide with a half-life of 76,000 years. ⁵⁹Ni has found many applications in isotope geology[?]. ⁵⁹Ni has been used to date the terrestrial age of meteorites and to determine abundances of extraterrestrial dust in ice and sediment. Nickel-60 is the daughter product of the extinct radionuclide ⁶⁰Fe (half-life = 1.5 Myr). Because the extinct radionuclide ⁶⁰Fe had such a long half-life, its persistence in solar_system materials at high enough concentrations may have generated observable variations in the isotopic composition of ⁶⁰Ni. Therefore, the abundance of ⁶⁰Ni present in extraterrestrial material may provide insight into the origin of the solar system and its early history.

The isotopes of nickel range in atomic weight from 52 amu (52-Ni) to 74 amu (74-Ni).

Precautions Exposure to nickel metal and soluble compounds should not exceed 0.05 mg/cm³ in nickel equivalents per 40-hour work week. Nickel sulfide fume and dust is believed to be carcinogenic.

Nickel carbonyl, [Ni(CO)₄], is an extremely toxic gas.

Sensitized[?] individuals may show an allergy to nickel affecting their skin. The amount of nickel which is allowed in products which come into contact with human skin is regulated by the European Union. In 2002 a report in the journal Nature researchers found amounts of nickel being emitted by 1 and 2 euro coins far in excess of those standards. This is believed to be due to a galvanic reaction.

External Links

• WebElements.com - Ni (http://www.webelements.com/webelements/elements/text/Ni/index)
• EnvironmentalChemistry.com - Ni (http://environmentalchemistry.com/yogi/periodic/Ni)
• Article in Nature on nickel emitted by euro coins (http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v419/n6903/abs/419132a_fs&filetype=&_UserReference=C0A804ED4653F39333F43C407C6F3D7FE5CE)
  

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A nickel is also a small coin made of or containing nickel; esp., a five-cent piece. It may also refer to the process of plating an object with the metal nickel.