The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Neptunium is a transuranium element, one of the elements found in Row 7 of the periodic table after uranium (atomic number 92). Neptunium's atomic number is 93, its atomic mass is 237.0482, and its chemical symbol is Np.
All isotopes of neptunium are radioactive, the longest lived being neptunium-237 with a half life of 2,140,000 years. The element exists as a silvery white metal with a melting point of 1,180°F (640°C) and a density of 20.45 grams per cubic centimeter. Neptunium is a fairly active element from which some unusual compounds, such as neptunium dialuminide (NpAl2) and neptunium beryllide (NpBe3), have been made. The element also forms more traditional compounds, such as neptunium dioxide (NpO2) and neptunium trifluoride (NpF3).
Neptunium occurs in only very small amounts in nature, as the byproduct of the radioactive decay of uranium. The element is now produced routinely for commercial use in nuclear reactors.
Neptunium was discovered in 1940 by a pair of physicists at the University of California at Berkeley, Edwin M. McMillan and Philip H. Abelson (1913-). They produced the element artificially by bombarding uranium atoms with neutrons. McMillan and Abelson suggested the name neptunium for the element in honor of the planet Neptune. Uranium, the element before neptunium in the periodic table, had earlier been named for the planet Uranus.
Neptunium and its compounds have been made for research purposes, but they have no commercial applications of any consequence.