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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 −21 seconds fluorine-15: 1.11 oxygen-12: 1.14 sodium-18: 1.34 lithium-10m2: 1.35 helium-10: 1.52 lithium-10: 2 carbon-8: 2 beryllium-13: 2.7 helium-7: 2.51 lithium-13: 3.3 lithium-10m1: 3.7 neon-16: 3.74 beryllium-6: 5 helium-9: 7 fluorine-16: 11 boron-9: 845
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 ...
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 ...
to be 1.9 × 10 19 years. [2] [3] Technetium and promethium (atomic numbers 43 and 61, respectively [a]) and all the elements with an atomic number over 82 only have isotopes that are known to decompose through radioactive decay. No undiscovered elements are expected to be stable; therefore, lead is considered the heaviest stable element.
However, a small amount of yttrium-90 will be found in secular equilibrium with its parent strontium-90 unless the two elements are separated from each other. 90 Sr decays into 90 Y which is a beta emitter with a half-life of 2.67 days. 90 Y is sometimes used for medical purposes and can be obtained either by the neutron activation of stable 89 ...
Environmental radioactivity is part of the overall background radiation and is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium-90 ( 90 Sr) and technetium-99 ( 99 Tc), are only found on Earth as a result of human activity, and some, like potassium-40 ( 40 K), are only present due to natural ...