Search results
Results from the WOW.Com Content Network
Hydrogen–deuterium exchange (also called H–D or H/D exchange) is a chemical reaction in which a covalently bonded hydrogen atom is replaced by a deuterium atom, or vice versa. It can be applied most easily to exchangeable protons and deuterons, where such a transformation occurs in the presence of a suitable deuterium source, without any ...
Hydrogen is the only element whose isotopes have different names that remain in common use today: 2 H is deuterium [6] and 3 H is tritium. [7] The symbols D and T are sometimes used for deuterium and tritium; IUPAC ( International Union of Pure and Applied Chemistry ) accepts said symbols, but recommends the standard isotopic symbols 2 H and 3 ...
Almost all the organic hydrogen is exchangeable to some extent. Isotopic exchange of organic hydrogen will reorder the distribution of deuterium and often incorporate external hydrogen. Generally, more mature materials are more heavily exchanged. With effective exchange, aliphatic hydrogen can finally reach isotopic equilibrium at the final stage.
An example is water, whose hydrogen-related isotopologues are: "light water" (HOH or H 2 O), "semi-heavy water" with the deuterium isotope in equal proportion to protium (HDO or 1 H 2 HO), "heavy water" with two deuterium atoms (D 2 O or 2 H 2 O); and "super-heavy water" or tritiated water (T 2 O or 3 H 2 O, as well as HTO [1 H 3 HO] and DTO [2 ...
Semiheavy water is the result of replacing one of the protium (normal hydrogen, 1 H) in normal water with deuterium (2 H; or less correctly, [1] D). [2] It exists whenever there is water with 1 H and 2 H in the mix. This is because hydrogen atoms (1,2 H) are rapidly exchanged between water molecules.
In contrast, exchange reactions between hydrogen and deuterium on the Haber–Bosch catalysts still take place at temperatures of −196 °C (−320.8 °F) at a measurable rate; the exchange between deuterium and hydrogen on the ammonia molecule also takes place at room temperature. Since the adsorption of both molecules is rapid, it cannot ...
Hydrogen deuteride is a minor component of naturally occurring molecular hydrogen. It is one of the minor but noticeable components of the atmospheres of all the giant planets, with abundances from about 30 ppm to about 200 ppm. HD has also been found in supernova remnants, [2] and other sources. [citation needed]
Thereafter, NIF management received many positive reviews and the project met the budgets and schedules approved by Congress. In October 2010, the project was named "Project of the Year" by the Project Management Institute , which cited NIF as a "stellar example of how properly applied project management excellence can bring together global ...