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

Answer 1

Answer:

Step-by-step explanation:

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