Nickel (Ni) is the 28th chemical found on the periodic table of elements - that is to say, nickel atoms always have 28 protons in their nucleus. This grey or even silverish metal is unusual in that it is magnetic, along with just three other metals (the most prominent being iron), and has been used by humans for several thousand years, though frequently confused with copper or silver for much of that time. Today nickel is highly useful for its magnetic properties as well as in coins, particularly the Canadian and American five-cent piece, the nickel.
- Chemical Characteristics -
Nickel is a grey metal which, in its natural form, occurs almost only in stable isotopes; in other words, it is not radioactive. (Several radioactive isotopes exist and can be manufactured, although only two, nickel-59 and nickel-61, have long half-lives.)
Nickel has been mined and used by humans for several thousand years; during this time, observers often failed to realize that they were dealing with a new and separate metal, instead regularly identifying nickel as silver or mis-classifying its ores (when taken out of the ground) as related to copper.
- Where Nickel is Found -
Even today, it is relatively difficult to find nickel in the ground. Its classification as a separate element, in European science, rested on a single European source of the metal, which the Germans referred to as the ore "Kupfernickel" - so named because its apparent resemblance to copper.
Currently, about one-third of the world's nickel production occurs in Sudbury, Ontario, Canada, which was long the leading producer of all nickel. The other major global supplier are the Norilsk mining complexes in Siberia, Russia. Smaller producers can be found in Australia and Indonesia, followed by New Caledonia. The price of nickel on global commodities exchanges can fluctuate wildly based on changes in supply as well as in demand. For example, during the last three years, the value of the nickel metal contained in a single five-cent piece (a nickel coin) has varied from both substantially more to somewhat less than the face value of the coin. When coins are worth markedly more than their face value, they often become targets for melting down into base metal for resale, a process which is currently illegal in North America.
Nickel is a relatively scarce commodity on Earth, at least in large amounts. However, it is produced by stars and often found in meteors in higher proportions than on the Earth itself. In keeping with these observations, the largest of Earth's nickel deposits, such as that of Sudbury, are believed to have originated in ancient cometary or meteor impact events. Given its prevalence in the early solar system, it is possible that larger amounts of nickel can be found in the Earth's molten core; this region, however, is obviously unreachable by mining activities.
- Key Uses -
Nickel has a number of key uses. It is one of the metals which is used to form stainless steel alloys. In addition, it sees frequent use in magnets and minting coins. Even here, however, it is principally used in alloys rather than in pure form: the majority of the metal in the American nickel, for example, is actually less expensive copper. (In the same way, American pennies are made up mostly of inexpensive zinc, with a copper surface.)
Although plants and bacteria contain small amounts of nickel, in general more than small exposures to nickel are toxic to human beings. Certain nickel compounds may cause cancer, and nickel carbonyl gas, in particular, is known to be highly toxic. Even beyond toxicity, it is possible to develop allergies to nickel, causing skin problems through exposure to common nickel sources, such as coins and some jewellery.