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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.
Beryllium-10 (10 Be) is a radioactive isotope of beryllium. It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen. [ 3 ] [ 4 ] [ 5 ] Beryllium-10 has a half-life of 1.39 × 10 6 years, [ 6 ] [ 7 ] and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV.
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.
Of the 26 "monoisotopic" elements that have only a single stable isotope, all but one have an odd atomic number—the single exception being beryllium. In addition, no odd-numbered element has more than two stable isotopes, while every even-numbered element with stable isotopes, except for helium, beryllium, and carbon, has at least three.
The time required to lose half of a quantity of a given nuclide through radioactive decays, the half-life, is a measure of how stable an isotope is. [10] Nuclides can be visually represented on a table (Segré chart or table of nuclides) where the proton number is plotted against the neutron number. [11]
The amount of liquid-vapor equilibrium fractionation for hydrogen isotopes is about 8x that of oxygen isotopes at Earth surface temperatures, which reflects the relative mass differences of the two isotope systems: 2 H is 100% heavier than 1 H, 18 O is 12.5% heavier than 16 O. Above the boundary layer, there is a transition zone with relative ...
Carbon-14 is a radioactive isotope of carbon, with a half-life of 5,730 years [28] [29] (which is very short compared with the above isotopes), and decays into nitrogen. [30] In other radiometric dating methods, the heavy parent isotopes were produced by nucleosynthesis in supernovas, meaning that any parent isotope with a short half-life ...