Naturally occurring samarium includes 15.1% of radioactive isotope 14'Sm, which decays by a emission. One gram of natural Sm gives 89 + 5 a decays per second. From these data calculate the half-life of the isotope 14'sm and give its uncertainty. - The decay chain chain 139CS 139Ba 139La is observed from an initially pure sample of 1 mCi of 13CS. The half-lives are: 9.5 min for 1CS, and 82.9 min for 13Ba, and 139 13La is stable. What is the maximum 13Ba activity and when does it occur? Hint: Use the equation in Q.1 above.