SOLUTION: A certain radioactive substance decays exponentially and has a half-life of 78 years. What fraction of the substance will decay in 234 years?

Question 323981: A certain radioactive substance decays exponentially and has a half-life of 78 years. What fraction of the substance will decay in 234 years?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A certain radioactive substance decays exponentially and has a half-life of 78 years. What fraction of the substance will decay in 234 years?
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A(t) = Ao*(1/2)^(t/78)
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A(234) = Ao*(1/2)^(234/78)
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A(234) = Ao*0.125
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Ans: 1/8 will be remaining;
7/8 of the original amount will have decayed.
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Cheers,
Stan H.
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