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.
Ordinary water consists of two hydrogen atoms and one oxygen atom. Heavy water consists of two deuterium atoms and one oxygen atom. Deuterium is an isotope of hydrogen; both have the same number of protons, and therefore have the same atomic number. However, deuterium has one neutron in its nucleus while hydrogen has none and so deuterium is heavier than hydrogen. Thus a molecule of heavy water has a mass of 20 atomic units while an ordinary water molecule has a mass of 18 units. Pure heavy water is 10% more dense than ordinary water; it freezes at 38.8°F (3.8°C) and boils at 214.5°F (101.4°C). It is not radioactive and occurs naturally in nature in limited quantities.
Heavy water, which can be harvested from natural water sources or created from electrolyzed water, is used as a moderator in nuclear power plants. The uranium-235 in the reactor can capture neutrons only if they are moving slowly enough; thus a moderator is needed to slow the particles. High-speed neutrons hit the deuterium and lose some of their momentum, slowing the neutron. Ironically, slowing down the neutrons will increase the nuclear fission rate. Ordinary water is used as a moderator as well, but absorbs most neutrons instead of just slowing them through collisions; these reactors must use enriched uranium to be able to sustain nuclear fission. Other uses for deuterium include quantum effect experiments, extensive use in molecular structure studies, superconductivity experiments, chemical kinetics, nuclear magnetic resonance shift studies, dipole moment studies, ESR hyperfine interactions, geochemical experiments, and experiments dealing with growth and morphology of plants and animals.