SOLUTION: Hi I need help with this problem. Thanks The half-life of lead is 22 yr. What is its decay rate?

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Question 251551: Hi I need help with this problem. Thanks
The half-life of lead is 22 yr. What is its decay rate?
Answer by MRperkins(300) About Me  (Show Source):
You can put this solution on YOUR website!
1%2F2=e%5E%28r%2A22%29
ln(1/2)=22r <---take the natural log of both sides
%28ln%281%2F2%29%2F22%29=r
r=-.0315 which shows a decay of .0003% or 3.15 * 10^-4 %
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