Nickel is a silver-white metal. It is a little golden colored. It is easily polished (made shiny). It is magnetic. It is not magnetic when heated above 355 °C (671 °F). It is not soft like many other metals. It can be stretched into wires easily. It is not radioactive.
Nickel is in several oxidation states. +2 [Nickel(II)]is the most common. +3 [Nickel(III)] also is common. Nickel in its +2 oxidation state is green. Nickel(II) chloride is a common +2 oxidation state compound. Nickel(II) oxide is normally dark green, but sometimes it is gray. This is because some of the nickel is in the +3 oxidation state (nickel(III). Nickel(III) compounds are oxidizing agents. They also are grayish. Nickel compounds can be green, blue, gray, or black.
Nickel is not normally found as a metal in the ground. Sometimes meteorites have nickel and iron metal in them. Normally nickel is in minerals. Nickel hydroxides, sulfides, and silicates are common ores. Russia makes the most nickel.
Nickel was found when a copper-colored ore did not make copper metal. Later it was found out that the ore was actually a nickel ore. Nickel was isolated as a metal in 1751. At first, the copper colored nickel ore was the only source. Later, it was made as a byproduct of cobalt blue making.
Nickel is made from sulfide ores. They are heated to melt them and concentrate them. They are also separated by oils. Nickel is made from its sulfide by heating it in air. This oxidizes the sulfide to sulfur dioxide, leaving liquid nickel behind. This nickel is not pure. Only about 75% of it is nickel.
Nickel can be made purer. It can react with carbon monoxide to make nickel carbonyl, a gas when warm. All the impurities are left behind. The nickel carbonyl is blown into nickel pellets, where it coats the pellets with pure nickel and puts out carbon monoxide. The carbon monoxide is reused (used again).
As a metal[change]
Nickel is used in metal alloys. Stainless steel contains nickel. Nickel is also used in nichrome, a name for a nickel-chromium alloy. Nickel is used in coins such as nickels. It is used in magnets. Nickel is used in special expensive alloys called superalloys.
As chemical compounds[change]