heavy hydrogen

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Related to heavy hydrogen: tritium


 (H) [hi´dro-jen]
a chemical element, atomic number 1, atomic weight 1.00797. (See Appendix 6.) It exists as the mass 1 isotope (protium, or light or ordinary hydrogen), mass 2 isotope (deuterium, heavy hydrogen), and mass 3 isotope (tritium).
hydrogen cyanide an extremely poisonous colorless liquid or gas, HCN, a decomposition product of various naturally occurring glycosides and a common cause of cyanide poisoning. Inhalation of the gas can cause death within a minute. Called also hydrocyanic acid.
heavy hydrogen deuterium.
hydrogen ion concentration the degree of concentration of hydrogen ions (the acid element) in a solution. Its symbol is pH, and it expresses the degree to which a solution is acidic or alkaline. The pH range extends from 0 to 14, pH 7 being neutral, a pH of less than 7 indicating acidity, and one above 7 indicating alkalinity. See also acid-base balance.
hydrogen peroxide H2O2, an antiseptic with a mildly antibacterial action. A 3 per cent solution foams on touching skin or mucous membrane and appears to have a mechanical cleansing action.
hydrogen sulfide H2S, a poisonous gas with an offensive smell, released from decaying organic material, natural gas, petroleum, and sulfur deposits, and sometimes used as a chemical reagent.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


(hi'dro-jen) [ hydro- + -gen] H
A colorless, odorless, tasteless, gaseous chemical element, possessing one valence electron, atomic weight (mass) 1.0079, specific gravity 0.069, atomic number 1. A liter of the gas at sea level and at 0°C weighs 0.08988 g. There are three isotopes of hydrogen (protium, deuterium, and tritium), having atomic weights of approx. 1, 2, and 3, respectively.
CAS # 1333-74-0


Hydrogen is present in the sun and stars. Even though it is the most abundant element in the known universe, its concentration in the earth's atmosphere is only 0.00005%. Hydrogen occurs in its free state (in natural gases and volcanic eruptions) only in minute quantities. It occurs principally on the earth as water (hydrogen oxide, H2O) and is a constituent of all hydrocarbons. Hydrogen is present in all acids and in ionic form is responsible for the properties characteristic of acids. Hydrogen is present in nearly all organic compounds and is a component of all carbohydrates, proteins, and fats.


It is highly flammable and used in the oxyhydrogen flame in welding, in hydrogenation of oils for solidifying purposes, as a reducing agent, and in many syntheses.

hydrogen cyanide

Hydrocyanic acid.

hydrogen dioxide

Hydrogen peroxide.

heavy hydrogen


hydrogen iodide

Hydriodic acid.

hydrogen peroxide

H2O2, a colorless syrupy liquid with an irritating odor and acrid taste. It decomposes readily, liberating oxygen. Because light is particularly effective in decomposing H2O2, it must be stored in tightly sealed glass jars in a dark place. Synonym: hydrogen dioxide


It is used as a commercial bleaching agent; as an oxidizing and reducing agent; and, in a 3% aqueous solution, as a mild antiseptic, germicide, and cleansing agent.

CAS # 7722-84-1

hydrogen sulfide

H2S, a poisonous, flammable, colorless compound with a characteristic odor of rotten eggs. Synonym: sulfurated hydrogen Synonym: hydrosulfuric acid
CAS # 7783-06-4

sulfurated hydrogen

Hydrogen sulfide
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
The very high ratio of heavy hydrogen (deuterium) to the common sort in what little water vapor remains says that there was once 100 times or so more, enough to make a wading pool over the surface, if not an ocean.
Investigating the hydrogen isotopes in the plaster provided a link to one suspect, whose living room air was similarly enriched in heavy hydrogen, a team reported in January in the Journal of Forensic Sciences.
In both sets of experiments, the researchers used chilled acetone in which hydrogen atoms had been replaced by deuterium, or heavy hydrogen, which fuses more readily than ordinary hydrogen does.
Last year, nuclei of heavy hydrogen and of gold were slammed against each other at RHIC.
The wire cage vaporizes, collapsing inward and radiating X-rays toward a sesame-seed-size capsule of heavy hydrogen. This heats and squeezes the hydrogen until some of it fuses into helium and tritium nuclei.
There, scientists zapped clusters of atoms of deuterium, or heavy hydrogen, with brief but extremely powerful laser pulses.
researchers who measured the ratio of heavy hydrogen, or deuterium, to ordinary hydrogen in water in Comet Hale-Bopp.
The target typically consists of a vapor of heavy hydrogen isotopes (tritium and deuterium) encased in plastic.
When a current passes between the electrodes, the water molecules break apart and spectacular amounts of deuterium nuclei (a heavy hydrogen isotope) cram into the palladium metal, where Pons and Fleischmann continue to argue fusion occurs.