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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 ...
Specific activity (symbol a) is the activity per unit mass of a radionuclide and is a physical property of that radionuclide. [ 1 ] [ 2 ] It is usually given in units of becquerel per kilogram (Bq/kg), but another commonly used unit of specific activity is the curie per gram (Ci/g).
But 90 Sr has a 30-year half-life, and 89 Sr a 50.5-day half-life. Thus in the 50.5 days it takes half the 89 Sr atoms to decay, emitting the same number of beta particles as there were decays, less than 0.4% of the 90 Sr atoms have decayed, emitting only 0.4% of the betas. The radioactive emission rate is highest for the shortest lived ...
Strontium-90 has a shorter half-life, produces less power, and requires more shielding than plutonium-238, but is cheaper as it is a fission product and is present in a high concentration in nuclear waste and can be relatively easily chemically extracted. Strontium-90 based RTGs have been used to power remote lighthouses. [1]
90 Sr produces approximately 0.93 watts of heat per gram (it is lower for the form of 90 Sr used in RTGs, which is strontium fluoride). [77] However, 90 Sr has one third the lifetime and a lower density than 238 Pu, another RTG fuel. The main advantage of 90 Sr is that it is significantly cheaper than 238 Pu and is found in nuclear waste.
Jennaleah “Jenna” Hin, 17, of Henderson, Nevada, was reported missing since Dec. 30 after she reportedly left home following a family dispute
The longest half-lives among them are 1.387 million years for beryllium-10, 99.4 thousand years for calcium-41, 1599 years for radium-226 (radium's longest-lived isotope), 28.90 years for strontium-90, 10.51 years for barium-133, and 5.75 years for radium-228. All others have half-lives of less than half a year, most significantly shorter.
The trip up to level 90 is fairly guided, with quests and bread crumb trails to lead you to the best places to level up and collect experience. But after you hit max level, you're on your own for ...