Natural Abundance of the Lithium Isotopes

Abstract

The natural abundance ratio of the lithium isotope of mass 7 to the isotope of mass 6 has been determined from the density and x-ray data for certain crystals. Consideration of the maximum limits of variation of this ratio in nature and the error assignments of the data used in this calculation have resulted in the value 11.53\ifmmode\pm\else\textpm\fi{}0.29. This value disagrees with the mass spectrometric and optical determinations. Some of the possible errors in the mass spectrometric work are considered.