Nickel is a very hard, magnetic, metallic element. It is almost silver-white. Nickel, capable of a high polish, does not rust easily. Its chemical symbol is Ni. Axel Cronstedt, a Swede, is credited with discovering nickel in 1751.
   Nickel is seldom used in its pure form but is employed as an alloy with other metals. Since it provides an extremely hard surface, nickel is used in electroplating. Certain types of electric batteries use nickel-alloy electrodes.
   Nickel-steel alloys are important in combining iron and steel into the . strongest, toughest steels. Nickel is employed more in steel alloys than for any other purpose.
   Stainless steel combines iron, chromium, and nickel. Invar alloy is used in measuring tapes and watch springs. Alnico is an alloy of aluminum, nickel, cobalt, and iron. Alnico magnets are more magnetic than steel magnets. Copper and nickel are merged into monel metal. It is used in restaurant steam tables, kitchen sinks, and cabinets. Monel metal is easily kept bright and clean.
   The United States coin called a nickel contains 75 percent copper and 25 percent nickel. A Canadian nickel contains more nickel. Canada produces more nickel than all other countries combined. The chief nickel ore is pentlandite.
   Nickel's atomic number is 28. Its atomic weight is 58.71.