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Naturally occurring europium (63 Eu) is composed of two isotopes, 151 Eu and 153 Eu, with 153 Eu being the most abundant (52.2% natural abundance).While 153 Eu is observationally stable (theoretically can undergo alpha decay with half-life over 5.5×10 17 years), 151 Eu was found in 2007 to be unstable and undergo alpha decay. [4]
Naturally occurring europium is composed of two isotopes, 151 Eu and 153 Eu, which occur in almost equal proportions; 153 Eu is slightly more abundant (52.2% natural abundance). While 153 Eu is stable, 151 Eu was found to be unstable to alpha decay with a half-life of 5 +11
The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. This is a list of chemical elements by the stability of their isotopes. Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable. [1] Overall, there are 251 known stable isotopes in ...
There are no stable nuclides with mass numbers 5 or 8. There are stable nuclides with all other mass numbers up to 208 with the exceptions of 147 and 151, which are represented by the very long-lived samarium-147 and europium-151. (Bismuth-209 was found to be radioactive in 2003, but with a half-life of 2.01 × 10 19 years.)
Research at Laboratori Nazionali del Gran Sasso showed that europium-151 decays to promethium-147 with the half-life of 5 × 10 18 years; [29] later measurements gave the half-life as (4.62 ± 0.95(stat.) ± 0.68(syst.)) × 10 18 years. [30] It has been shown that europium is "responsible" for about 12 grams of promethium in the Earth's crust. [29]
Periodic table for looking up element numbers (atomic number). These isotope tables show all of the known isotopes of the chemical elements, arranged with increasing atomic number from left to right and increasing neutron number from top to bottom.
At least 3,300 nuclides have been experimentally characterized [1] (see List of radioactive nuclides by half-life for the nuclides with decay half-lives less than one hour). A nuclide is defined conventionally as an experimentally examined bound collection of protons and neutrons that either is stable or has an observed decay mode.
However, some even neutron numbers also have only one stable nuclide; these numbers are 0 (1 H), 2 (4 He), 4 (7 Li), 84 (142 Ce), 86 (146 Nd) and 126 (208 Pb), the case of 84 is special, since 142 Ce is theoretically unstable to double beta decay, and the nuclides with 84 neutrons which are theoretically stable to both beta decay and double ...