Nickel

Source of the photo
http://periodictable.com/Elements/028/index.html
Author of the description
Gruiz Katalin

Atomic number

28

Atomic mass

58.71 g.mol -1

Electronegativity

1.8

Density

8.9 g.cm-3 at 20°C

Melting point

1453 °C

Boiling point

2913 °C

Vanderwaals radius

0.124 nm

Ionic radius

0.069 nm (+2) ; 0.06 nm (+3)

Isotopes

10

Electronic shell

[ Ar ] 3d8 4s2

Energy of first ionisation

735 kJ.mol -1

Energy of second ionisation

1753 kJ.mol -1

Energy of third ionisation

3387 kJ.mol -1

Standard potential

- 0.25 V

Discovered by

Alex Constedt 1751

 



Nickel is silvery-white. hard, malleable, and ductile metal. It is of the iron group and it takes on a high polish. It is a fairly good conductor of heat and electricity. In its familiar compounds nickel is bivalent, although it assumes other valences. It also forms a number of complex compounds. Most nickel compounds are blue or green. Nickel dissolves slowly in dilute acids but, like iron, becomes passive when treated with nitric acid. Finely divided nickel adsorbs hydrogen.

Applications

The major use of nickel is in the preparation of alloys. Nickel alloys are characterized by strength, ductility, and resistance to corrosion and heat. About 65 % of the nickel consumed in the Western World is used to make stainless steel, whose composition can vary but is tipycally iron with aroun 18% chromium and 8% nichel. 12 % of all the nichel consumed goes into superalloys. The remaining 23% of consumption is divided between alloy steels, rechargeable batteries, catalysts and other chemicals, coinage, foundry products, and plating.
Nickel is easy to work and can be drawn into wire. It resist corrosion even at high temperatures and for this reason it is used in gas turbines and rocket engines. Monel is an alloy of nickel and copper (e.g. 70% nichel, 30% copper with traces of iron, manganese and silicon), which is not only hard but can resist corrosion by sea water, so that it is ideal for propeller shaft in boats and desalination plants.