Question

The half-life of lead is 18 years. How long will it take for the sample of this substance to decay to 15%?a. Find your k

Answer 1

We are given

Half Life = 18 years

To solve for k

`\begin{gathered} 0.5=e^(-18k) \\ ln(0.5)=-18k \\ k=-(ln(0.5))/(18) \\ k=0.0385081767 \end{gathered}`