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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 longest-lived of these isotopes, and the most relevantly studied, are 90 Sr with a half-life of 28.9 years, 85 Sr with a half-life of 64.853 days, and 89 Sr (89 Sr) with a half-life of 50.57 days. All other strontium isotopes have half-lives shorter than 50 days, most under 100 minutes.
isotope half-life 10 −24 seconds hydrogen-5 86(6) lithium-4: 91(9) hydrogen-4: 139(10) nitrogen-10: 143(36) oxygen-11: 198(12) helium-10: 260(40) hydrogen-6: 294(67) lithium-5: 370(30) fluorine-14: 500(60) boron-7: 570(14) nitrogen-11: 585(7) helium-5: 602(22) beryllium-16: 650(130) hydrogen-7: 652(558) nitrogen-11m: 690(80) boron-21 > 760 ...
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. Strontium has physical and chemical properties similar to those of its two vertical ...
Rubidium–strontium dating. The rubidium–strontium dating method (Rb–Sr) is a radiometric dating technique, used by scientists to determine the age of rocks and minerals from their content of specific isotopes of rubidium (87 Rb) and strontium (87 Sr, 86 Sr). One of the two naturally occurring isotopes of rubidium, 87 Rb, decays to 87 Sr ...
Strontium. Strontium-90 is a commonly used beta emitter used in industrial sources. It decays to yttrium-90, which is itself a beta emitter. It is also used as a thermal power source in radioisotope thermoelectric generator (RTG) power packs. These use heat produced by radioactive decay of strontium-90 to generate heat, which can be converted ...
Apart from 91 Y, 87 Y, and 90 Y, with half-lives of 58.51 days, 79.8 hours, and 64 hours, respectively; all other isotopes have half-lives of less than a day and most of less than an hour. [29] Yttrium isotopes with mass numbers at or below 88 decay mainly by positron emission (proton → neutron) to form strontium (Z = 38) isotopes. [29]
The Windscale fire of 10 October 1957 was the worst nuclear accident in the United Kingdom's history, and one of the worst in the world, ranked in severity at level 5 out of 7 on the International Nuclear Event Scale. [ 1 ] The fire was in Unit 1 of the two-pile Windscale site on the north-west coast of England in Cumberland (now Sellafield ...