Question 691823
A certain radioactive isotope has a half-life of approximately 850 years. How many years to the nearest year would be required for a given amount of this isotope to decay 20% of that amount?
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A(t) = Ao(1/2)^(t/850)
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0.20 = (1/2)^(t/850)
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(t/850) = log(0.2)/(0.5)
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t/850 = 2.3219
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t = 1974 years
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Cheers,
Stan H>
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