Question

A radio active isotope decays according to the exponential decay equations where t is in days.

Answer 1

Given the equation

`(a)/(2) =ae^(-9.876t) \\ \\ (1)/(2) =e^(-9.876t) \\ \\ -9.876t=\ln\left( (1)/(2) \right)=-0.6931 \\ \\ t= (-0.6931)/(-9.876) =0.0702`

Therefore, the half life of the radioactive substance is 0.0702 days = 1.68 hours = 1 hour, 41 minutes, 4 seconds.