Question

Iodine-125 is radioactive and has a half life of 60.25 days. What percentage of a sample would be left after 107. days? Round your answer to 2 significant digits. % X + ?

Answer 1

no of half lives(n) = total time half life time

                        = 107/60.25  

                         n = 1.776

The amount of left = initial amount/2^n

                          2^n   = inital amount/amount left

                         2^1.776   = inital amount/amount left

           amount left/ inital amount = 1/2^1.776     

amount left/ inital amount   = 0.29

amount left/ inital amount %   = 29% >>>>answer