The Unit of Atomic Weight

Abstract

DISCUSSING the unit of atomic weight before Section A (Physics) at the meeting of the British Association in London on Sept. 28, Dr. F. W. Aston contrasted the point of view of the physicist and the chemist. The painstaking research in recent years to determine whether the atomic weights of complex elements vary with their origin and to effect the separation of isotopes has proved conclusively that for practical purposes variation in Nature is negligible, and has justified the decision of the Committee of the International Union of Chemistry to retain the old relative meaning of the words ‘element’ and ‘atomic weight’. There is little reason to alter the present unit of atomic weight, O = 16, which has figured so long in chemical literature.