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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 ...
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes chemical over nuclear.
Radioactive nonprimordial, but naturally occurring on Earth. 61 347 Carbon-14 (and other isotopes generated by cosmic rays) and daughters of radioactive primordial elements, such as radium, polonium, etc. 41 of these have a half life of greater than one hour. Radioactive synthetic half-life ≥ 1.0 hour). Includes most useful radiotracers. 662 989
The result is that the molecules are either constitutional isomers or stereoisomers solely based on isotopic location. The term isotopomer was first proposed by Seeman and Paine in 1992 to distinguish isotopic isomers from isotopologues (isotopic homologues). [1] [2]
Water molecules with a lighter isotope are slightly more likely to evaporate and less likely to fall as precipitation, [14] so Earth's freshwater and polar ice have slightly less (0.1981%) 18 O than air ( 0.204% ) or seawater ( 0.1995% ).
Isotopologues of ethanol (CH 3 CH 2 OH) with mass 47, corresponding to a single isotopic substitution. Isotopologues with a heavy isotope at different positions are called isotopomers. Ethanol has 2 H- and 13 C-isotopomers. Chemical reactions in biological processes are controlled by enzymes that catalyze the conversion of substrate to product ...
Isotopologues are molecules that have the same chemical composition, but differ only in their isotopic composition. Methane has ten stable isotopologues: 12 CH 4, 13 CH 4, 12 CH 3 D, 13 CH 3 D, 12 CH 2 D 2, 13 CH 2 D 2, 12 CHD 3, 13 CHD 3, 12 CD 4 and 13 CD 4, among which, 12 CH 4 is an unsubstituted isotopologue; 13 CH 4 and 12 CH 3 D are singly substituted isotopologues; 13 CH 3 D and 12 CH ...