Answer:
The half life of the radioactive substance is 277 hours.
Step-by-step explanation:
initial mass, No = 100 mg
mass decayed = 2% = 2 mg
Mass remained , N = 98 mg
time, t = 8 hours
Let the half life is T.
Use the equation of radioactivity
[tex]N = No\times e^{\frac{-0.693 t}{T}}\\\\98 = 100 \times e^{\frac{-0.693\times 8}{T}}\\\\0.98 = e^{\frac{-5.54}{T}}\\\\ln 0.98 = -\frac{5.54}{T}\\\\-0.02= -\frac{5.54}{T}\\\\T = 277 hours[/tex]
