Given
Half life is t=5.125 days
To find
The decay constant
Explanation
The decay constant is given by
[tex]\begin{gathered} \lambda=\frac{0.693}{t} \\ \Rightarrow\lambda=\frac{0.693}{5.125} \\ \Rightarrow\lambda=0.135 \end{gathered}[/tex]Conclusion
The decay constant is 0.135 /day
