Question

After 8 yr there will be ?g of a radioactive substance

Answer 1

`\begin{gathered} 9=18e^(-3k) \\ 0.5=e^(-3k) \\ ln(0.5)=-3k \\ k=-(ln(0.5))/(3)=0.23105 \end{gathered}`

Thus;

`\begin{gathered} A=18e^(-0.23105*8) \\ A=2.835 \end{gathered}`

Thus, the remaining amount is 2.835 g