Periodic Table of the Elements
KTF-SPLIT    EniG. 

Glossary
Appendix
PDF Table
Awards
Links
Software
My Software

 
  EDITORS:
  English English

  Aditya Vardhan
  Eni Generalic
  Français French

  Michel Ditria
  Hrvatski Croatian

  Eni Generalic
  Marija Bralic
  Slobodan Brinic
  Deutch German

  Marc Hens
  Italiano Italian

  editors wanted
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
Molybdenum Molybdène Molibden Molibdeno Molybdän

 
Atomic number: 42
Group numbers: 6
Period: 5
 
Discovery date: 1778
Mo

Molybdenum
NEIGHBOURS
23
V
 24
Cr
 25
Mn
41
Nb
 42
Mo
 43
Tc
73
Ta
 74
W
 75
Re


New address! - http://www.periodni.com/en/ - Please update your Bookmarks

Molybdenum was discovered by Carl William Scheele (Sweden) in 1778. The origin of the name comes from the Greek word molybdos meaning lead. It is silvery white, very hard metal, but is softer and more ductile than tungsten.
Bottom TRANSITION ELEMENT: CHROMIUM GROUP Top

Relative atomic mass: 95.94(1) Electronic configuration: [Kr] 4d5 5s1
Formal oxidation number: +6 Electronegativities: 2.16
Thermal conductivity: 138 W m-1 K-1 Electrical resistivity (20 °C): 5.34 μΩcm
Atomic radius: 136.3 pm Standard state (20 °C): solid
Density (g dm-3): 10220 (293 K)
9330 (m.p.)		 Molar volume (cm3 mol-1): 9.39 (293 K)
10.28 (m.p.)


Bottom THERMAL PROPERTIES Top

Melting point: 2623 °C Heat of fusion: 27.6 kJ mol-1
Boiling point: 4639 °C Heat of vaporization: 589.9 kJ mol-1
Critical temperature: 9177 °C Heat of atomization: 656.55 kJ mol-1


Bottom IONIZATION ENERGIES AND ABUNDANCE Top

1st ionization energy: 684.32 kJ mol-1 Abundance of element (air): - ppm
2nd ionization energy: 1559.21 kJ mol-1 Abundance of element (Earth's crust): 1 ppm
3rd ionization energy: 2617.67 kJ mol-1 Abundance of element (oceans): 0.01 ppm


Bottom ISOTOPES Top

Isotopes Relative atomic mass Abundance (%)
92Mo91.906810(4)14.84(4)
94Mo93.905088(2)9.25(3)
95Mo94.905841(2)15.92(5)
96Mo95.904679(2)16.68(5)
97Mo96.906021(2)9.55(3)
98Mo97.905408(2)24.13(7)
100Mo99.907477(6)9.63(3)


Bottom MINERALS AND USES Top

Molybdenum is found in the minerals molybdenite (MoS2) and wulfenite (MoO4Pb). Its alloys are used in aircraft, missiles and protective coatings in boiler plate. The price of 99.7 % pure molybdenum pellets is 96.90 € for 500 g.

Bottom REDUCTION POTENTIALS Top

Balanced half-reaction   Eo / V      Annotation
MoVI + e- = MoV +0.43  4.6 mol dm-3 H2SO4
MoIII + 3e- = Mo(s) - 0.2  
H2MoO4(aq) + 2H+ + e- = MoO2+ + 2H2O +0.4  
HMoO4- + 3H+ + 2e- = MoO2 + 2H2O +0.429  
MoO42- + 4H+ + 2e- = MoO2 + 2H2O +0.606  
HMoO4- + 7H+ + 3e- = Mo3+ + 4H2O +0.390  
MoO42- + 8H+ + 3e- = Mo3+ + 4H2O +0.508  
MoO42- + 8H+ + 6e- = Mo(s) + 4H2O +0.154  
MoO42- + 4H2O + 6e- = Mo(s) + 8OH- - 1.05  

 

Sources of literature are given on the bibliographic page.
If you have comments, corrections or suggestions about this site, please send me a e-mail.

Top FACULTY OF CHEMICAL TECHNOLOGY IN SPLIT Eni Generalic PERIODIC TABLE OF THE ELEMENTS version 1.7 Top
Glossary of chemical terms Periodic Table of the Elements Calculating the molecular weight
Last modified: 01.04.2003
Copyright © 1998-2003 by Eni Generalic