Niobium

Niobium Element Properties

d40
Zr
Zirconium
d41
Nb
Niobium
d42
Mo
Molybdenum
General
NameNiobium
SymbolNb
Number41
Group Number5
GroupTransition metals
Blockd
Density8.57 g/cm3
Atomic Weight92.9064 g/mol
Atomic Volume10.87 cm3/mol
Discover1801


States
StateSolid
Melting Point2750 K
Boiling Point5017 K
Triple PointNil
Critical PointNil
Heat of Fusion30 kJ/mol
Heat of Vaporization689.9 kJ/mol


Energies
First Ionization Energy663.8 kJ/mole
Second Ionization Energy1381.7 kJ/mole
Third Ionization Energy2416 kJ/mole
Electronegativity1.6
Electron Affinity86.2 kJ/mole
Specific Heat0.26 J/gK
Heat Atomization726 kJ/mole atoms


Oxidation and Electrons
Shells2,8,18,12,1
Electron Configuration[Kr] 4d4 5s1
Minimum Oxidation Number-1
Maximum Oxidation Number5
Minimum Common Oxidation Number0
Maximum Common Oxidation Number5


Appearance and Characteristics
Crystal Structurecubic body centered
Characteristicssoft
Colorsilvery-white
Usesstainless steels, magnets
Hardnessmohs
ToxicityNone


Reactions
Reaction with Airnone, w/ht =>Nb2O3
Reaction with 6M HClNone
Reaction with 15M HNO3None
Reaction with 6M NaOHNone


Other Forms
Number of Isotopes1
HydrideNbH NbH2
OxideNbO NbO2 Nb2O5
ChlorideNbCl3 NbCl4 NbCl5


Radius
Atomic Radius146 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)86 pm


Conductivity
Thermal Conductivity53.7 J/m-sec-deg
Electrical Conductivity80 1/mohm-cm
Polarizability15.7 A3


Abundance
Sourcecolumbite (oxide)
Relation Abundance Solar System-0.156 log
Abundance Earth's Crust1.3 log


d40
Zr
Zirconium
d41
Nb
Niobium
d42
Mo
Molybdenum