ChemiPlus Logo

Dictionary - Training

Niobium

41
Nb
92.9064
Niobium
 General | States | Energies | Oxidation & Electrons | Appearance & Characteristics | Reactions | Other Forms Radius | Conductivity | Abundance

General:

Name: Niobium Symbol: Nb
Group: Trans. Met. Atomic weight: 92.9064
Density @ 293 K: 8.57 g/cm3 Atomic volume: 10.87 cm3/mol
Group: Trans. Met. discovered: 1801

States:

state (s, l, g): s
melting point: 2741.2 K boiling point: 5031 K
Heat of fusion: 26.40 kJ/mol Heat of vaporization: 682.0 kJ/mol

Energies:

1st ionization energy: 663.8 kJ/mole
electronegativity: 1.6 2nd ionization energy: 1381.7 kJ/mole
electron affinity: 86.2 kJ/mole 3rd ionization energy: 2416 kJ/mole
Specific heat: 0.26 J/gK heat atomization: 726 kJ/mole atoms

Oxidation & Electrons:

Shells: 2,8,18,12,1 electron configuration: [Kr] 4d4 5s1
minimum oxidation number: -1 maximum oxidation number: 5
min. common oxidation no.: 0 max. common oxidation no.: 5

Appearance & Characteristics:

structure: bcc: body-centered cubic color: silvery-white
uses: stainless steels, magnets toxicity:
hardness: mohs characteristics: soft

Reactions:

reaction with air: none, w/ht =>Nb2O3
reaction with 6M HCl: none reaction with 6M HCl: none
reaction with 15M HNO3: reaction with 6M NaOH: none

Other Forms:

number of isotopes: 1 hydride(s): NbH NbH2
oxide(s): NbO NbO2 Nb2O5 chloride(s): NbCl3 NbCl4 NbCl5

Radius:

ionic radius (2- ion): pm ionic radius (1- ion): pm
atomic radius: 146 pm ionic radius (1+ ion): pm
ionic radius (2+ ion): pm ionic radius (3+ ion): 86 pm

Conductivity:

thermal conductivity: 53.7 J/m-sec-deg
electrical conductivity: 80 1/mohm-cm polarizability: 15.7 A^3

Abundance:

source: columbite (oxide)
rel. abund. solar system: -0.156 log abundance earth's crust: 1.3 log
cost, pure: 18 $/100g cost, bulk: $/100g