Question

A radioactive isotope has a half life of 4.51 days. If 12.63 grams are now present, how much will be left after 15

days?

Answer 1

Explanation:

`f=ir^t\\ \\ (1)/(2)=r^(4.51)\\ \\ ln(0.5)=4.51lnr\\ \\ r=e^{(ln0.5)/(4.51)}\\ \\ r\approx 0.8575\\ \\ f(15)=12.63(0.8575^(15)\\ \\ f(15)\approx 1.26g`