出典:Wiktionary
niobium (countable かつ uncountable, 複数形 niobiums)
出典:Wikipedia
出典:『Wikipedia』 (2011/08/08 18:23 UTC 版)
Niobium ( /naɪˈoʊbiəm/) or columbium (/kəˈlʌmbiəm/), is a chemical element with the symbol Nb and atomic number 41. A rare, soft, grey, ductile transition metal, niobium is found in the minerals pyrochlore, the main commercial source for niobium, and columbite. The name comes from Greek mythology: Niobe, daughter of Tantalus.