A veterinary oncology clinic uses a therapeutic radioisotope to treat thyroid tumors in dogs.
A canine patient is administered an initial activity of 8.4 GBq8.4\text{ GBq}8.4 GBq of this radioisotope. The physical half-life of the isotope is 8.0 days8.0\text{ days}8.0 days and its biological half-life within the dog is 24 days24\text{ days}24 days.
For radiation safety reasons, the dog must remain in isolation at the clinic and cannot be discharged to its owners until the remaining activity of the isotope in its body falls below 1.8 GBq1.8\text{ GBq}1.8 GBq.
Determine whether the dog can be safely discharged after 13.0 days13.0\text{ days}13.0 days.