SOLUTION: A certain radioactive element will decay at certain rate. If 50.0% of the original element sample remains after 9.0 days, what is the decay rate?

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Question 1088677: A certain radioactive element will decay at certain rate. If 50.0% of the original element sample
remains after 9.0 days, what is the decay rate?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
y=a%2Ab%5Ex

%281%2F2%29=1%2Ab%5E9
b%5E9=1%2F2
9%2Alog%28%28b%29%29=log%28%281%2F2%29%29
log%28%28b%29%29=%281%2F9%29log%28%281%2F2%29%29

log%28%28b%29%29=-0.03345
highlight_green%28b=0.926%29
This means, about 7.4% decrease per day