SOLUTION: A radioactive substance has a half-life of 3.5 days. A scientist starts with 80 grams of the decaying substance. How much is left after 8.2 days?

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Question 1104585: A radioactive substance has a half-life of 3.5 days. A scientist starts with 80 grams of the decaying substance. How much is left after 8.2 days?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A radioactive substance has a half-life of 3.5 days. A scientist starts with 80 grams of the decaying substance. How much is left after 8.2 days?
A(t) = (Ao)(1/2)^(t/3.5)
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A(t) = Ao(1/2)^(t/3.5)
A(8.2) = 80(1/2)^(8.2/3.5)
A(8.2) = 80(1/2)^2.343
A(8.2) = 15.77 grams
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Cheers,
Stan H.