Nickel ( ) is a metallic chemical element with the symbol Ni and atomic number 28. It is corrosion-resistant, finding many uses as in alloys and as a plating.

Characteristics

Similar to the massive forms of chromium, aluminium and titanium, nickel is a very reactive element, but is slow to react in air at normal temperatures and pressures. Due to its permanence in air and its inertness to oxidation, it is used in coins, for plating iron, brass, etc., for chemical apparatus, and in certain alloys, such as German silver.

Nickel is magnetic, and is very often accompanied by cobalt, both being found in meteoric iron. It is chiefly valuable for the alloys it forms, especially many superalloys, and particularly stainless steel. Nickel is also a naturally magnetostrictive material, meaning that in the presence of a magnetic field, the material undergoes a small change in length. In the case of Nickel, this change in length is negative (contraction of the material), which is known as negative magnetostriction.

The most common oxidation state of nickel is +2, though 0, +1, +3 and +4 Ni complexes are observed. It is also thought that a +6 oxidation state may exist, however, results are inconclusive.

The unit cell of nickel is a face centered cube with a lattice parameter of 0.352 nm giving a radius of the atom of 0.125 nm.

Nickel-62 is the most stable nuclide of all the existing elements; it is more stable even than iron-56.

History

The use of nickel is ancient, and can be traced back as far as 20 BC. Bronzes from what is now Syria had a nickel content of up to 100%.Fact: date=September 2008 Further, there are Chinese manuscripts suggesting that "white copper" (i.e. baitung) was used in the Orient between 1700 and 1400 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. Nickel is used today as common household utensils, such as silverware.Fact: date=September 2008

Minerals containing nickel (e.g. German: Kupfernickel, Old or Low German: Kopper-Nickel or Koppernickel, meaning copper and ("Nick"), or false copper) were of value for colouring glass green. In 1751, Baron Axel Fredrik Cronstedt was attempting to extract copper from kupfernickel (now called niccolite), and obtained instead a white metal that he called nickel.Fact: date=September 2008

In the United States, the term "nickel" or "nick" was originally applied to the copper-nickel Indian cent coin introduced in 1859. Later, the name designated the three-cent coin introduced in 1865, and the following year the five-cent shield nickel appropriated the designation, which has remained ever since. Coins of pure nickel were first used in 1881 in Switzerland. 1