General: |
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Name: Niobium
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Symbol: Nb
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Group: Trans. Met.
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Atomic weight: 92.9064
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Density @ 293 K: 8.57 g/cm3
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Atomic volume: 10.87 cm3/mol
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Group: Trans. Met.
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discovered: 1801
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States: |
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state (s, l, g): s
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melting point: 2741.2 K
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boiling point: 5031 K
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Heat of fusion: 26.40 kJ/mol
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Heat of vaporization: 682.0 kJ/mol
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Energies: |
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1st ionization energy: 663.8 kJ/mole
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electronegativity: 1.6
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2nd ionization energy: 1381.7 kJ/mole
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electron affinity: 86.2 kJ/mole
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3rd ionization energy: 2416 kJ/mole
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Specific heat: 0.26 J/gK
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heat atomization: 726 kJ/mole atoms
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Oxidation & Electrons: |
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Shells: 2,8,18,12,1
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electron configuration: [Kr] 4d4 5s1
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minimum oxidation number: -1
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maximum oxidation number: 5
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min. common oxidation no.: 0
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max. common oxidation no.: 5
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Appearance & Characteristics: |
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structure: bcc: body-centered cubic
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color: silvery-white
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uses: stainless steels, magnets
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toxicity:
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hardness: mohs
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characteristics: soft
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Reactions: |
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reaction with air: none, w/ht =>Nb2O3
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reaction with 6M HCl: none
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reaction with 6M HCl: none
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reaction with 15M HNO3:
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reaction with 6M NaOH: none
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Other Forms: |
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number of isotopes: 1
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hydride(s): NbH NbH2
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oxide(s): NbO NbO2 Nb2O5
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chloride(s): NbCl3 NbCl4 NbCl5
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Radius: |
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ionic radius (2- ion): pm
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ionic radius (1- ion): pm
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atomic radius: 146 pm
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ionic radius (1+ ion): pm
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ionic radius (2+ ion): pm
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ionic radius (3+ ion): 86 pm
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Conductivity: |
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thermal conductivity: 53.7 J/m-sec-deg
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electrical conductivity: 80 1/mohm-cm
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polarizability: 15.7 A^3
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Abundance: |
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source: columbite (oxide)
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rel. abund. solar system: -0.156 log
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abundance earth's crust: 1.3 log
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cost, pure: 18 $/100g
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cost, bulk: $/100g
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