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| Question 1058052:  Radioactive Decay. A radioactive isotope, selenium (75Se), used in the creation of medical images of the pancreas, has a half-life of 119.77 days. If 250 milligrams are given to a patient, how many milligrams, A, are left after 34 days?
 Answer by ankor@dixie-net.com(22740)
      (Show Source): 
You can put this solution on YOUR website! A radioactive isotope, selenium (75Se), used in the creation of medical images of the pancreas, has a half-life of 119.77 days. If 250 milligrams are given to a patient, how many milligrams, A, are left after 34 days?
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 Use the radioactive decay formula; A = Ao*2(-t/h), where:
 A = Amt remaining after t time
 Ao = Initial amt (250 ml)
 t = time of decay (34 days)
 h = half-life of substance (119.77 days)
 :
 A = 250*2^(-34/119.77)
 Using a calc
 A = 250 * .82138
 A = 205.345 ml after 34 days
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