Periodic Table of the Elements
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Bottom FACULTY OF CHEMICAL TECHNOLOGY o PERIODIC TABLE OF THE ELEMENTS Bottom
  A B C D E F G H I J K L M N O P R S T U V X Z  
Periodic Table of the Elements Tableau périodique des éléments Periodni sustav elemenata Tavola periodica degli elementi Das Periodensystem der Elemente
Niobium Niobium Niobij Niobio Niob

 
Atomic number: 41
Group numbers: 5
Period: 5
 
Discovery date: 1801
Nb

Niobium
NEIGHBOURS
22
Ti
 23
V
 24
Cr
40
Zr
 41
Nb
 42
Mo
72
Hf
 73
Ta
 74
W


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Niobium was discovered by Charles Hatchett (England) in 1801. The origin of the name comes from the Greek word Niobe meaning daughter of Tantalus in Greek mythology (tantalum is closely related to niobium in the periodic table). It is shiny white, soft, ductile metal. Exposed surfaces form oxide film.
Bottom TRANSITION ELEMENT: VANADIUM GROUP Top

Relative atomic mass: 92.90638(2) Electronic configuration: [Kr] 4d4 5s1
Formal oxidation number: +3 +5 Electronegativities: 1.6
Thermal conductivity: 53.7 W m-1 K-1 Electrical resistivity (20 °C): 12.5 μΩcm
Atomic radius: 142.9 pm Standard state (20 °C): solid
Density (g dm-3): 8570 (293 K)
7830 (m.p.)		 Molar volume (cm3 mol-1): 10.84 (293 K)
11.87 (m.p.)


Bottom THERMAL PROPERTIES Top

Melting point: 2477 °C Heat of fusion: 27.2 kJ mol-1
Boiling point: 4744 °C Heat of vaporization: 680.19 kJ mol-1
Critical temperature: 8427 °C Heat of atomization: 722.819 kJ mol-1


Bottom IONIZATION ENERGIES AND ABUNDANCE Top

1st ionization energy: 652.13 kJ mol-1 Abundance of element (air): - ppm
2nd ionization energy: 1381.68 kJ mol-1 Abundance of element (Earth's crust): 11 ppm
3rd ionization energy: 2416.01 kJ mol-1 Abundance of element (oceans): 0.00001 ppm


Bottom ISOTOPES Top

Isotopes Relative atomic mass Abundance (%)
93Nb92.906378(2)100


Bottom MINERALS AND USES Top

Niobium occurs in a mineral columbite. It is used in stainless steel alloys for nuclear reactors, jets and missiles. Used as an alloy with iron and nickel. It can be used in nuclear reactors and is known to be superconductive when alloyed with tin, aluminium or zirconium. The price of 99.8 % pure niobium pieces is 47.20 € for 100 g.

Bottom REDUCTION POTENTIALS Top

Balanced half-reaction   Eo / V      Annotation
NbV + 2e- = NbIII - 0.373  6 mol dm-3 H2SO4
Nb3+ + 3e- = Nb(s) - 1.1  
Nb2O5(s) + 10H+ + 10e- = 2Nb(s) + 5H2O - 0.65  
NbO3+ + 2H+ + 2e- = Nb3+ + H2O - 0.343  
NbO(SO4)2- + 2H+ + 2e- = Nb3+ + H2O + 2SO42- - 0.1  
NbO(SO4)2- + 2H+ + 5e- = Nb(s) + H2O + 2SO42- - 0.63  

 

Sources of literature are given on the bibliographic page.
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