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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.
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 ...
Archaeological materials, such as bone, organic residues, hair, or sea shells, can serve as substrates for isotopic analysis. Carbon, nitrogen and zinc isotope ratios are used to investigate the diets of past people; these isotopic systems can be used with others, such as strontium or oxygen, to answer questions about population movements and cultural interactions, such as trade.
In contrast, the proton numbers for which there are no stable isotopes are 43, 61, and 83 or more (83, 90, 92, and perhaps 94 have primordial radionuclides). [3] This is related to nuclear magic numbers , the number of nucleons forming complete shells within the nucleus, e.g. 2, 8, 20, 28, 50, 82, and 126.
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
Owing to both of these advantages, the method of isotope dilution is regarded among chemistry measurement methods of the highest metrological standing. [1] Isotopes are variants of a particular chemical element which differ in neutron number. All isotopes of a given element have the same number of protons in each atom.
Equilibrium isotope fractionation is the partial separation of isotopes between two or more substances in chemical equilibrium. Equilibrium fractionation is strongest at low temperatures, and (along with kinetic isotope effects) forms the basis of the most widely used isotopic paleothermometers (or climate proxies): D/H and 18 O/ 16 O records from ice cores, and 18 O/ 16 O records from calcium ...
For indium and rhenium, the long-lived radionuclide is actually the most abundant isotope in nature, and the stable isotope is less abundant. In two additional cases ( bismuth [ 2 ] and protactinium ), mononuclidic elements occur which are not monoisotopic because the naturally occurring nuclide is radioactive, and thus the element has no ...