I Stable and radioactive isotopes

Kaste, I., Friedland, A., Stiirup, S., 2003. Using stable and radioactive isotopes to trace atmospherically deposited Pb in montane fmest soils. Environ. Sci. Technol. 37, 3560—3567. 

Symbol Bk atomic number 97 atomic weight of most stable isotope 247.07 a transuranium radioactive element synthesized in the laboratory electronic configuration [Rn]5/97s2 oxidation states -i-3 and +4. Isotopes, half-hfe and decay modes are given below ... 

Isotope dilution methods, which predate activation procedures, have been and still are extensively applied to problems in all branches of chemistry. I liese methods arc among the most selective available to chemists. Both stable and radioactive nuclides are employed in the isotope dilution technique. Radioactive nuclides are the more convenient, however, because of the case with which (he concentration of the isotope can be de-... 

The most abundant isotope of carbon has a mass of 12 atomic mass units, 12C. A less abundant stable isotope is 13C. And much less abundant is the radioactive isotope t4C, also called radiocarbon. It is convenient to express the abundances of these rare isotopes in terms of ratios of the number of atoms of the rare isotope in a sample to the number of atoms of the abundant isotope. We call this ratio r, generally a very small number. To arrive at numbers of convenient magnitude, it is conventional to express the ratio in terms of the departure of r from the ratio in a standard, which I call. v, and to express this departure in parts per thousand of s. Thus the standard delta notation is... 

For a pair made of a radioactive isotope i and a stable isotope j of the same element (e.g., 14C/12C), it can be safely assumed that af = ctj. In this case, their ratio at steady-state may be written... 

Symbol Ce atomic number 58 atomic weight 140.115 a rare-earth metal a lanthanide series inner-transition /-block element metaUic radius (alpha form) 1.8247A(CN=12) atomic volume 20.696 cm /mol electronic configuration [Xe]4fi5di6s2 common valence states -i-3 and +4 four stable isotopes Ce-140 and Ce-142 are the two major ones, their percent abundances 88.48% and 11.07%, respectively. Ce—138 (0.25%) and Ce—136(0.193%) are minor isotopes several artificial radioactive isotopes including Ce-144, a major fission product (ti 284.5 days), are known. 

Symbol Np atomic number 93 atomic weight 237 (most stable isotope) a man-made transuranium radioactive element actinide series electron configuration [Rn]5/" 6di7s2 oxidation states +3, +4, -i-5 and +6 most stable valence... 

A and 1.04A corresponding to CN 6 and 8, respectively standard electrode potential, E° for Tbs+ -i- 3e <-> Tb is -2.28V one naturally-occurring stable isotope, Tb-159 (100%) twenty-five artificial radioactive isotopes in the mass range 140-158, 160-165 the longest-lived radioisotope, Tb-158, ti/2 180 years shortest-lived isotope, Tb-142, tm 0.60 sec. 

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