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Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal , strontium is a soft silver-white yellowish metallic element that is highly chemically reactive . The metal forms a dark oxide layer when it is exposed to air.
The alkaline earth metal strontium (38 Sr) has four stable, naturally occurring isotopes: 84 Sr (0.56%), 86 Sr (9.86%), 87 Sr (7.0%) and 88 Sr (82.58%). Its standard atomic weight is 87.62(1). Only 87 Sr is radiogenic ; it is produced by decay from the radioactive alkali metal 87 Rb , which has a half-life of 4.88 × 10 10 years (i.e. more than ...
Naturally occurring strontium is nonradioactive and nontoxic at levels normally found in the environment, but 90 Sr is a radiation hazard. [4] 90 Sr undergoes β − decay with a half-life of 28.79 years and a decay energy of 0.546 MeV distributed to an electron, an antineutrino, and the yttrium isotope 90 Y, which in turn undergoes β − decay with a half-life of 64 hours and a decay energy ...
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 ...
Isotope half-lives. The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes largerIsotopes are nuclides with the same number of protons but differing numbers of neutrons; that is, they have the same atomic number and are therefore the same chemical element.
A map of 90 Sr contamination around Chernobyl has been published by the IAEA. [1] Due to its very small neutron absorption cross section, Strontium-90 is poorly suited for thermal neutron induced nuclear transmutation as a way of disposing of it.
687.1 lead-210: 22.3 700 strontium-90: 28.79 909 curium-243: 29.1 920 caesium-137: 30.17 952 10 9 seconds (gigaseconds) isotope half-life years 10 9 seconds
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 ...