Half life
Level
pending
I have a radioactive isotope that has a cpm of 640 and has a half life of 3 days. Calculate how many days it takes for the cpm rate to decrease to 80cpm.
The answer is 9.
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1 solution
640/2=320/2=160/2=80 I have halved the cpm 3 times to get 80 and since the half life is 3 days the number of days it takes for the radioactive isotope to have 80cpm is 9 days.