Nickel

Nickel

Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile. Pure nickel shows a significant chemical activity that can be observed when nickel is powdered to maximize the exposed surface area on which reactions can occur, but larger pieces of the metal are slow to react with air at ambient conditions due to the formation of a protective oxide surface. Even then, nickel is reactive enough with oxygen so that native nickel is rarely found on Earth's surface, being mostly confined to the interiors of larger nickel–iron meteorites that were protected from oxidation during their time in space. On Earth, such native nickel is always found in combination with iron, a reflection of those elements' origin as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's inner core.

The use of nickel (as a natural meteoric nickel–iron alloy) has been traced as far back as 3500 BC. 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. The element name comes from a mischievous sprite of German miner's mythology, Nickel (similar to Old Nick), that personified the fact that copper-nickel ores resisted refinement into copper. An economically important source of nickel is the iron ore limonite, which often contains 1-2% nickel. Nickel's other important ore minerals include garnierite, and pentlandite. Major production sites include Sudbury region in Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific and Norilsk in Russia.

Because of nickel's slow rate of oxidation at room temperature, it is considered corrosion-resistant. Historically this has led to its use for plating metals such as iron and brass, to its use for chemical apparatus, and its use in certain alloys that retain a high silvery polish, such as German silver. About 6% of world nickel production is still used for corrosion-resistant pure-nickel plating. Nickel was once a common component of coins, but has largely been replaced by cheaper iron for this purpose, especially since the metal is a skin allergen for some people.

Nickel is one of four elements that are ferromagnetic around room temperature. Alnico permanent magnets based partly on nickel are of intermediate strength between iron-based permanent magnets and rare-earth magnets. The metal is chiefly valuable in the modern world for the alloys it forms; about 60% of world production is used in nickel-steels (particularly stainless steel). Other common alloys, as well as some new superalloys, make up most of the remainder of world nickel use, with chemical uses for nickel compounds consuming less than 3% of production.[4] As a compound, nickel has a number of niche chemical manufacturing uses, such as a catalyst for hydrogenation. Enzymes of some microorganisms and plants contain nickel as an active site, which makes the metal an essential nutrient for them.

Occurrence


On Earth, nickel occurs most often in combination with sulfur and iron in pentlandite, with sulfur in millerite, with arsenic in the mineral nickeline, and with arsenic and sulfur in nickel galena. Nickel is commonly found in iron meteorites as the alloys kamacite and taenite.

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): (Ni, Mg)3Si2O5(OH)4. The second are magmatic sulfide deposits where the principal ore mineral is pentlandite: (Ni, Fe)9S8.

Australia and New Caledonia have the biggest estimate reserves (45% all together).

In terms of World Resources, identified land-based resources averaging 1% nickel or greater contain at least 130 million tons of nickel (about the double of known reserves). About 60% is in laterites and 40% is in sulfide deposits.

Based on geophysical evidence, most of the nickel on Earth is postulated to be concentrated in the Earth's outer core and inner core. Kamacite and taenite are naturally occurring alloys of iron and nickel. For kamacite the alloy is usually in the proportion of 90:10 to 95:5 although impurities such as cobalt or carbon may be present, while for taenite the nickel content is between 20% and 65%. Kamacite and taenite occur in nickel iron meteorites.

Symbol		Ni
Atomic Number		28
Atomic Weight		58.6934
Oxidation States		+2,+3
Electronegativity, Pauling		1.91
State at RT		Solid, Metal
Melting Point, K		1726
Boiling Point, K		3005

Interesting Facts about Nickel

• 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. 
• 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.

Appearance and Characteristics

Harmful effects:

Nickel and its compounds are considered to be carcinogenic. Approximately 10 to 20 percent of people are sensitive to nickel. Repeated contact with it leads to skin complaints (dermatitis). Such people should avoid contact with nickel, which can be found in jewelry.

Workers who have breathed very large amounts of nickel compounds have developed chronic bronchitis and lung and nasal cancers.

Nickel carbonyl is a very toxic gas.

Characteristics:

• Nickel is a hard, silvery-white metal, which is malleable and ductile.
• The metal can take on a high polish and it resists tarnishing in air.
• Nickel is ferromagnetic and is a fair conductor of heat and electricity.
• Most nickel compounds are blue or green.

Uses of Nickel

• The majority of nickel is used in corrosion-resistant alloys, such as stainless steel.
• Tubing made from a copper-nickel alloy is used in desalination plants. This alloy is naturally resistant to corrosion by seawater and to biofouling.
• Many coins contain nickel.
• Nickel steel is used for burglar-proof vaults and armor plate.
• Nickel is also used in batteries – for example NiCd (nickel-cadmium) and Ni-MH (nickel-metal hydride) rechargeable batteries – and in magnets.

How to make your own nickel-iron battery. These batteries last for decades!

Reaction of nickel metal with nitric acid producing nickel nitrate and brown nitrogen dioxide gas. For some reason the video says nickel nitrate is blue. It is in fact green, as you can see.