Molar volume of ⁶Li, ⁷Li and natural Li in the liquid state

The densities of natural Li, concentrated ⁶Li and concentrated ⁷Li in the liquid state were each measured by the two-sphere-Archimedes method. The measured density of natural Li in the liquid state was in good agreement with previous data. From these data the molar volumes of natural Li, concentrated ⁶Li and concentrated ⁷Li in the liquid state were calculated. Among those three kinds of liquid Li, the molar volume changes in an almost common straight line with the variation of the temperature. This indicates that no isotope effect can be seen between the molar volume in the liquid state of ⁶Li and that of ⁷Li within the present experimental error. The simple model calculation of the molar volume of liquid Li was performed based on the hard sphere model immersed in the uniform electron gas. Calculated molar volumes agree with experimental ones.