Nickel(metal)

nickel metal

1. NICKEL

2.  Nickel was first isolated and classified as a chemical element in 1751 by  Axel Fredrik Cronstedt , who initially mistook its  ore for a  copper   mineral . Nickel  is a  chemical element  with symbol  Ni  and  atomic number  28 .  An iron–nickel mixture is thought to compose Earth's  inner core .

3. PHYSICAL PROPERTIES Phase solid Melting point 1728  K  ​(1455 °C, ​2651 °F) Boiling point 3003 K ​(2730 °C, ​4946 °F) Density   near  r.t. 8.908 g·cm −3 when liquid, at m.p. 7.81 g·cm −3 Heat of fusion 17.48  kJ·mol −1 Heat of vaporization 379 kJ·mol −1 Molar heat capacity 26.07 J·mol −1 ·K −1

4. The nickel atom has two  electron configurations , [ Ar ] 3d 8  4s 2  and [ Ar ] 3d 9  4s 1 , which are very close in energy – the symbol [ Ar ] refers to the  argon -like core structure. Naturally occurring nickel is composed of five stable  isotopes ; 58 Ni, 60 Ni, 61 Ni, 62 Ni and 64 Ni with 58 Ni being the most abundant (68.077%  natural abundance ).

5. Miscellanea Crystal structure ​ face-centered cubic  (fcc) Speed of sound thin rod 4900 m·s −1  (at r.t.) Thermal expansion 13.4 µm·m −1 ·K −1  (at 25 °C) Thermal conductivity 90.9 W·m −1 ·K −1 Electrical resistivity 69.3 nΩ·m (at 20 °C) Magnetic ordering ferromagnetic Young's modulus 200 GPa Shear modulus 76 GPa Bulk modulus 180 GPa Poisson ratio 0.31 Mohs hardness 4.0 Vickers hardness 638 MPa Brinell hardness 667–1600  MPa

6. Purification of nickel oxides to obtain the purest metal is performed via the  Mond process , which increases the nickel concentrate to greater than 99.99% purity.

7. Nickel is used in many specific and recognizable industrial and consumer products, including  stainless steel ,  alnico  magnets, coinage,  rechargeable batteries , electric guitar strings, microphone capsules, and special alloys APPLICATIONS:

8. The plant enzyme  urease  (an enzyme that assists in the hydrolysis of  urea ) contains nickel. Nickel can have an impact on human health through infectious diseases arising from nickel-dependent bacteria. [71]  Nickel released from  Siberian Traps  volcanic eruptions (site of the modern city of  Norilsk ) is suspected of having had a significant impact on the role played by  Methanosarcina , a genus of euryarchaeote archaea that produced methane during the  biggest extinction event on record . Biological role

9. Nickel carbonyl , [ Ni(CO)4 ], is an extremely toxic gas . Sensitivity to nickel may also be present in patients with  pompholyx .  Nickel is an important cause of contact allergy, partly due to its use in jewellery intended for  pierced ears . TOXICITY:

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