Neptunium

From Citizendium, the Citizens' Compendium
Jump to: navigation, search
This article is a stub and thus not approved.
Main Article
Talk
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
Properties [?]
 
This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved, citable version. These unapproved articles are subject to a disclaimer.
Neptunium
237.0462



  Np
93
1s22s22p63s23p63d104s24p6 4d105s25p64f145d106s26p65f46d17s2
[ ? ] Transuranic element:
Properties:
Silvery metal. Chemically reactive.
Hazard:
Radioactive


Neptunium is a chemical element, having the chemical symbol Np. Its atomic number (the number of protons) is 93. It has a standard atomic weight of 237.0462 g•mol −1 and it is a solid in its elemental form.

Neptunium is considered a member of the "Transuranic" class of elements. At a pressure of 101.325 kPa, it has a boiling point of 3,900 °C and a melting point of 644 °C.

History

Neptunium was the first synthetic transuranium element of the actinide series to be discovered. In 1940, Edwin McMillan and Philip H. Abelson produced the isotope 239Np at the Berkeley Radiation Laboratory of the University of California, Berkeley by bombarding uranium with cyclotron-produced, slow moving neutrons.[1]

References

  1. Neptunium From the website of the Los Alamos National Laboratory (LANL)