Nickel (28)

Nickel is found as a constituent in most meteorites and often serves as one of the criteria for distinguishing a meteorite from other minerals. Iron meteorites, or siderites, may contain iron alloyed with from 5 to nearly 20% nickel. The USA 5-cent coin (whose nickname is "nickel") contains just 25% nickel. Nickel is a silvery white metal that takes on a high polish. It is hard, malleable, ductile, somewhat ferromagnetic, and a fair conductor of heat and electricity.

Nickel carbonyl, [Ni(CO)4], is an extremely toxic gas and exposure should not exceed 0.007 mg M-3.

•Name: Nickel
•Symbol: Ni
•Atomic number: 28
•Atomic weight: 58.6934
•Standard state: solid at 298 K
•CAS Registry ID: 7440-02-0
•Group in periodic table: 10
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: lustrous, metallic, silvery tinge
•Classification: Metallic

Historical information

Nickel was discovered by Axel Fredrik Cronstedt at 1751 in Sweden. Origin of name is from the German word "kupfernickel" meaning Devil's copper or St Nicholas's (Old Nick's) copper. Minerals containing nickel were of value for coloring glass green. The mineral used for coloring glass was called kupfernickel (false copper). Nickel was discovered by Baron Axel Frederik Cronstedt in 1751 in a mineral called niccolite. Apparently, he had expected to extract copper from this mineral but got none at all, obtaining instead a white metal that he called nickel after the mineral from which it was extracted.

Physical properties

•Melting point: 1728 [or 1455 °C (2651 °F)] K
•Boiling point: 3186 [or 2913 °C (5275 °F)] K
•Density of solid: 8908 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d8.4s2
•Shell structure: 2.8.16.2
•Term symbol: 3F4

Isolation

It is not normally necessary to make nickel in the laboratory as it is available readily commercially. Small amounts of pure nickel can be isolated in the laboratory through the purification of crude nickel with carbon monoxide. The intermediate in this process is the highly toxic nickel tetracarbonyl, Ni(CO)4. The carbonyl decomposes on heating to about 250°C to form pure nickel powder.

Ni + 4CO (50°C) → Ni(CO)4 (230°C) → Ni + 4CO

The Ni(CO)4 is a volatile complex which is easily flushed from the reaction vessel as a gas leaving the impurities behind. Industrially, the Mond process uses the same chemistry. Nickel oxides are reacted with "water gas", a mixture of CO + H2). Reduction of the oxide with the hydrogen results in impure nickel. This reacts with the CO component of the water gas to make Ni(CO)4 as above. Thermal decomposition leaves pure nickel metal.

Nickel (English) Nickel (French) Nickel (Deutsch) Nichel (Italian) Niquel (Spanish) Nickel (Swedish)

Interesting Facts:

Nickel is ferromagnetic at room temperature, just like its close periodic table neighbors iron and cobalt.

Nickel is 100 times more concentrated below Earth’s crust than in it. Nickel is believed to be the second most abundant element in the earth’s core, with iron most abundant by a large margin.

Nickel is the main metal in Mu-metal, which has the fascinating property of magnetic shielding. Magnets will normally attract metals such as iron. If you place Mu-metal between magnet and metal, the attraction disappears. This is because very little magnetic field is transmitted through Mu-metal. Mu-metal is approximately 80% nickel, 20% iron with a little molybdenum. (5)

The strange properties of nickel’s alloys don’t end with Mu-metal. Nitinol is a nickel alloy, discovered in the 1960s, that remembers its previous shape. Heat this 1:1 nickel-titanium alloy to about 500 oC, and bend it into whatever shape you like; you could bend a wire to make your name. Then cool it and bend the wire into a spring. Heat the wire again and, remarkably, the spring disappears, and the first shape – in this case your name – returns.

Nickel is corrosion resistant – it is one of the elements used in stainless steel. The presence of nickel in meteorite metal means it would have stayed bright and shiny in the hands of ancient people for much longer than if nickel had been absent.

Until the invention of rare-earth magnets, such as neodymium-iron-boron, the strongest permanent magnets – Alnico magnets – were made from a nickel alloy: mainly aluminum, nickel, cobalt and iron. Unusually, Alnico magnets retain their magnetism even when heated until they glow red hot.

Supernova 2007bi was observed in 2007. One of the products of this supernova was nickel-56, synthesized during the explosion. Nickel of mass three times greater than our entire sun was made. Nickel-56 is radioactive, decaying to cobalt-56, which itself decays to stable iron-56