Neptunium

From Citizendium
Revision as of 17:04, 9 January 2021 by imported>Mark Widmer (Opening paragraph revised to new standard: Phase, symbol, atomic no., and std. atomic weight. Updated "solid" link from disambig page to appropriate page.)
Jump to navigation Jump to search
This article is a stub and thus not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
Properties [?]
 
This editable Main Article is under development and 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, typically found as a solid in its elemental form. It has the chemical symbol Np, atomic number (number of protons) Z = 93, and a standard atomic weight of 237.0462 g/mol.

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)