- a steel-gray metallic element resembling tantalum in its chemical properties; becomes a superconductor below 9 K; used chiefly in alloy steels. Symbol: Nb; atomic number: 41; atomic weight: 92.906; specific gravity: 8.4 at 20°C.
- a ductile white superconductive metallic element that occurs principally in columbite and tantalite: used in steel alloys. Symbol: Nb; atomic no: 41; atomic wt: 92.90638; valency: 2, 3, or 5; relative density: 8.57; melting pt: 2469±10°C; boiling pt: 4744°CFormer name: columbium
named by German scientist Heinrich Rose, who discovered it in 1844 in the mineral tantalum; so called because in Greek mythology Niobe was the daughter of Tantalus.
n. Symbol Nb
- A soft ductile metallic element that is used in steel alloys and superconductors. Atomic number 41.
- A soft, silvery, ductile metallic element that usually occurs in nature together with the element tantalum. It is used to build nuclear reactors, to make steel alloys, and to allow magnets to conduct electricity with almost no resistance. Atomic number 41; atomic weight 92.906; melting point 2,468°C; boiling point 4,927°C; specific gravity 8.57; valence 2, 3, 5. See Periodic Table.