A Revised Table of Abundances of the Elements.

The semiempirical abundance table of Suess and Urey has been very helpful to nuclear physicists in determining the relative importance of various mechanisms of nucleogenesis in contributing to the natural abundances of the elements. The table was based primarily on abundance determinations in chondritic meteorites, together with the hypothesis that the abundances of odd mass-number nuclides should lie on a smooth curve. It has recently become apparent that certain elements are over- or underabundant in the chondritic meteorites without apparent chemical reason. In order to throw additional light on such discrepancies and on certain less well-understood mechanisms of nucleogenesis, the abundance-curve has been re-examined, using some additional nucleogenesis-based criteria for the abundances of even massnumber nuclides, and a new table of abundances has been constructed. It was found necessary to change the Suess-Urey table substantially in the rare-earth region and in the lead region and to make isolated changes in the abundances of certain additional elements. Some conclusions have been drawn regarding the process of neutron capture on a fast time scale and the methods of production of bypassed heavy nuclei.