The rate of emission of alpha particles from radium

Abstract

A knowledge of the number, Z, of α particles disintegrations taking place in unit mass of radium in unit time is of considerable importance in the interpretation of radioactive changes, and, in particular, of the energy relations involved. The heat evolution of radium and its short-lived decomposition products has been studied by a number of workers. Most of the heat production is accounted for by the energy of the a particles and recoil atoms, and in any particular experiment an allowance may be made for the β and γ ray energy absorbed. The experimental results are in agreement with the energy calculated from the number and energy of the a particles if a value is assumed for Z of about 3.7 . 10 10 . If, on the other hand, the value 3.57.10 10 obtained by Rutherford and Geiger, or the value 3.40.1010 recently published by Geiger and Werner, be taken, the calculation leaves a considerable portion of the heating effect unaccounted for, and this would involve an unidentified heatproducing mechanism in the disintegration.