SOLUTION: A radioactive isotope, selenium, used in the creation of medical images of the pancreas, has a half-life of 119.77 days. If 100 milligrams are given to a patient, how many millig

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: A radioactive isotope, selenium, used in the creation of medical images of the pancreas, has a half-life of 119.77 days. If 100 milligrams are given to a patient, how many millig      Log On


   

Question 1157954: A radioactive isotope, selenium, used in the creation of medical images of the pancreas,
has a half-life of 119.77 days. If 100 milligrams are given to a patient, how many milligrams
are left after 20 days? Work must be shown!
Answer by ikleyn(52788) About Me  (Show Source):
You can put this solution on YOUR website!
.
The general formula is


    M = M0%2A%281%2F2%29%5E%28t%2F98%29,


where  M0  is the initial mass;  M is the current (remaining) mass, and "t" is time in days.



So, the answers (and the calculation work) are


    M = 100*((1/2)^(20/119.77)) = 89.07 grams.      ANSWER

Solved.