heavy water

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deuterium (do͞otērˈēəm), isotope of hydrogen with mass no. 2. The deuterium nucleus, called a deuteron, contains one proton and one neutron. Deuterium is also called heavy hydrogen, and water in which the hydrogen atoms are deuterium is called heavy water (deuterium oxide, D2O). Deuterons are sometimes used in particle accelerators, and heavy water is used in “swimming pool” nuclear reactors as a moderator.
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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Heavy Water


D2O, an isotopic species of water in which the light hydrogen atom 1H is replaced by its heavy isotope 2H, which is called deuterium (D).

Heavy water was first discovered in natural water by H. Urey and E. F. Osborn (USA) in 1932; the species was isolated by G. N. Lewis and R. MacDonald (USA) in 1933. The density of heavy water is greater than that of ordinary water, hence the name. Heavy water is found in natural water and in atmospheric precipitation in the ratio of one D atom to 5,000–7,000 H atoms. The techniques of mass spectrometry, densimetry, and infrared spectroscopy are used in determining the content of heavy water.

The physical properties of D2O differ markedly from those of H2O. Heavy water boils at 101.43°C and freezes at 3.82°C; its density is 1.104 g/cm3. The chemical properties of heavy water are very close to those of H2O, although certain reactions occurring in a D2O medium are retarded or accelerated, sometimes by a factor between 2 and 3. The principal industrial methods for producing heavy water are the isotopic exchange of water and hydrogen sulfide, the distillation of hydrogen, and multistep electrolysis.

Heavy water is used in nuclear physics and power engineering as a neutron moderator and heat-transfer agent in nuclear reactors; it also serves as a starting material in the production of deuterium. Heavy water is used in chemistry, biology, and hydrology as an isotope tracer. In organisms, even a small amount of heavy water has an inhibitory effect, while larger doses are lethal.

The term “heavy water” is also used for water containing heavy oxygen, where 16O has been replaced by the heavy isotopes 17O and 18O. It likewise applies to HDO, to tritiated water (T2O), and to HTO and DTO. In superheavy water, ‘H is replaced by the radioisotope 3H, known as tritium (T).


Kirshenbaum, I. Tiazhelaia voda. Moscow, 1953. (Translated from English.)
Kirshenbaum, I. Proizvodstvo tiazheloi vody. Moscow, 1961. (Translated from English.)
Kratkaia khimicheskaia entsiklopediia, vol. 1. Moscow, 1961. Pages 614–17.
Brodskii, A. I. Khimiia izotopov, 2nd ed. Moscow, 1957.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

heavy water

[′hev·ē ′wȯd·ər]
(inorganic chemistry)
A compound of hydrogen and oxygen containing a higher proportion of the hydrogen isotope deuterium than does naturally occurring water. Also known as deuterium oxide.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

heavy water

water that has been electrolytically decomposed to enrich it in the deuterium isotope in the form HDO or D2O
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
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Rae's management responsibilities grew throughout his career, first leading small teams, then as the head of Chemical Engineering Branch, 1963 to 1972; as heavy water program co-ordinator, 1972 to 1976; and as director of the Fuel and Materials Division 1977 to 1979.
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