niobium

[nahy-oh-bee-uhm]
noun Chemistry.
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.

Origin:
1835–45; < Neo-Latin; see Niobe, -ium

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World English Dictionary
niobium (naɪˈəʊbɪəm)
 
n
Former name: columbium 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°C
 
[C19: from New Latin, from Niobe (daughter of Tantalus), so named because it occurred in tantalite]

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Medical Dictionary

niobium ni·o·bi·um (nī-ō'bē-əm)
n.
Symbol Nb
A soft ductile metallic element that is used in steel alloys and superconductors. Atomic number 41; atomic weight 92.906; melting point 2,477°C; boiling point 4,744°C; specific gravity 8.57; valence 2, 3, 5.

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American Heritage
Science Dictionary
niobium   (nī-ō'bē-əm)  Pronunciation Key 
Symbol Nb
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.
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Encyclopedia Britannica
Encyclopedia

niobium

chemical element, refractory metal of Group Vb of the periodic table, used in alloys, tools and dies, and superconductive magnets. Niobium is closely associated with tantalum in ores and in properties.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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Example sentences
Niobium metal is used in jewelry and as an alloying agent in steel to increase its strength.
The inner niobium shell is shown in gray while the stainless-steel helium vessel is shown in blue.
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