Neptunium
From Citizendium - Reading time: 1 min
This article is about Neptunium. For other uses of the term Neptune, please see Neptune (disambiguation).
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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 its longest-lived isotope has a mass number of 237.
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[edit]
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[edit]
- ↑ Neptunium From the website of the Los Alamos National Laboratory (LANL)
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