131 iodine has a half-life of 8.04 days. assuming you start with a 1.53 mg sample of 131 iodine, how many mg will remain after 13.0 days?

Bbecause i need points 

Iwas in a argument about a certain class grade with my teacher. it was a ‘a-’when i felt that i deserved a ‘a’. i showed him (my teacher) why i felt i derserved so. i questioned what i got wrong and showed him what i learned. i look back to that teacher with nothing but love and support because that’s the class that i actually learned the most. the moral of the story is to see where the other person is coming from and what they have done. also, when in a conflict, never attack the persons character. this will just make the argument end poorly.