E. Rutherford
Mar 1, 1929
Citations
6
Influential Citations
62
Citations
Journal
Nature
Abstract
BY the kindness of Dr. Aston, I have had the opportunity of inspecting his photographs showing the isotopes of lead obtained from the radioactive mineral bröggerite. As he concludes, it seems highly probable that the isotope of mass 207 is mainly due to actinium lead, and that the actinium series has its origin in an isotope of uranium—a suggestion independently put forward by several investigators on other evidence. Since six α particles are emitted in the successive changes from protactinium to the end product actinium lead, the atomic weight of protactinium should be 231. The direct determination of the atomic weight of this element number 91 now in progress in the laboratory of Prof. Hahn in Berlin should afford a crucial test of the accuracy of this deduction.