“…Similarly the increases in the Sn m /Mo 99 , Sn 125 /Mo 99 , Sb m /Mo 99 , and I 131 /Mo 99 activity ratios are 100, 75, 20.5, and 1.65, respectively. 2 The increase in the 9-hr Sb/Mo 99 activity ratio in going from thermal to 14-Mev fission was 38. Since this increase lies between that observed for Sn 126 and that observed for Sb 127 , we conclude that the 9-hr Sb should be assigned to mass 126.…”