Tablets of KI were distributed to people living around Chernobyl seven days after the nuclear reactor explosion occurred, to help flush radioactive 131I isotope out of their bodies. 131I has a half-life of 8 days.
a) What percentage of the 131I released by the explosion would have remained by that time? Use the first order kinetic equation: [A] = [A]o e-kt
b) How long would it have taken for 99.5% of the released 131I to undergo radioactive decay?