SOLUTION: A radioactive sample with a mass of 80mg has a half life of 3 days. How long does it take for the sample to decay to 5mg? I got this far 5=80(1/2)^t/3 not sure what to d

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Question 1167953: A radioactive sample with a mass of 80mg has a half life of 3 days.
How long does it take for the sample to decay to 5mg?

I got this far 5=80(1/2)^t/3
not sure what to do after this.

Answer by ikleyn(52802)   (Show Source): You can put this solution on YOUR website!
.

The mass ratio   =  =  = .


Four half-periods:  3*4 = 12 days.

This problem is for easy MENTAL solution.



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