SOLUTION: A substance decomposes radioactively. It's half-life is 32 years. Find the constant k int eh decay formula.

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Question 306634: A substance decomposes radioactively. It's half-life is 32 years. Find the constant k int eh decay formula.
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
A substance decomposes radioactively. It's half-life is 32 years. Find the constant k int eh decay formula.
.
Exponential decay:
N = Noe^(kt)
where
N amount after t time
No initial amount
k is rate of decay
t is time (years)
.
Let x = initial amount
then
(1/2)x = xe^(k*32)
Dividing both sides by x:
(1/2) = e^(k*32)
Take ln of both sides:
ln(1/2) = k*32
ln(1/2)/32 = k
-0.02166 = k