Answer:
[tex]t_{1/2} \approx 9.6\,days[/tex]
Step-by-step explanation:
The time constant of the radioactive constant is:
[tex]\tau = \frac{1}{0.072}\,days[/tex]
[tex]\tau = 13.889\,days[/tex]
The half-life of the substance is:
[tex]t_{1/2} = \tau \cdot \ln 2[/tex]
[tex]t_{1/2} = (13.889\,days)\cdot \ln 2[/tex]
[tex]t_{1/2} \approx 9.6\,days[/tex]
