Niobium - chemistry.

Niobium - chemistry. Niobium or Columbium, symbol Nb, steel-gray, lustrous, ductile, and malleable metallic element. The atomic number of niobium is 41. Niobium is one of the transition elements of the periodic table (see Periodic Law). This metal was discovered in 1801 by the British chemist Charles Hatchett. The element was named after Niobe, the daughter of Tantalus in Greek mythology. Niobium burns when heated in air and combines with nitrogen, hydrogen, and the halogens. It resists the actions of most acids. Its principal use is as an alloying element in stainless steel, to which it lends additional corrosion resistance, particularly at high temperatures. Niobium ranks about 32nd in natural abundance among the elements in crustal rock. It occurs, associated with the similar element tantalum, in various minerals, the most important of which is called columbite or tantalite, depending on which of the two elements predominates. Pure niobium has excellent characteristics as a construction material in nuclear power plants. Although niobium is found in many parts of the world, a large proportion of the world production comes from Nigeria and the Democratic Republic of the Congo (DRC, formerly Zaire). Niobium melts at about 2477°C (about 4491°F), boils at about 4744°C (about 8571°F), and has a specific gravity of 8.57. The atomic weight of niobium is 92.906. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.