SOLUTION: a certain element has a half-life of 15 years. if there was 1200mg originally, find the remaining amount after 5 years/

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Question 953715: a certain element has a half-life of 15 years. if there was 1200mg originally, find the remaining amount after 5 years/
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
General Model, y=p%2Ae%5E%28-kt%29

ln%28y%29=ln%28p%29-kt, skipping over a step;
-kt=ln%28y%29-ln%28p%29
kt=ln%28p%29-ln%28y%29
Take two separate directions from that step:

k=ln%28p%2Fy%29%2Ft and t=ln%28p%2Fy%29%2Fk.

The half-life data will give you k;
the decay situation data will give you y using the general model formula.


(Sometimes students want to be able to calculate half-life using other given data, so that is why the formula for t).