Molecular Weight Comparisons from Density and X-Ray Data. The Atomic Weights of Calcium and Fluorine

Abstract

Molecular weights have been compared by combination of the x‐ray and density data for the crystals, calcite, diamond, lithium fluoride, sodium chloride, and potassium chloride. By assumption of the chemical atomic weights of carbon, chlorine, potassium, lithium, and sodium, values for the atomic weights of calcium and fluorine have been calculated. The method employed consists of a series of independent calculations from the results of which final weighted average values have been taken for the atomic weights of calcium and fluorine. This has yielded 40.0849±0.0030 and 18.9967±0.0013, respectively. These values are most probably the most precise values for these constants at the present time. From the results of the present work it becomes apparent that the determination of atomic weights from comparison of molecular weights by combination of density and x‐ray data is as reliable as other standard atomic weight procedures.