Melting points and boiling points for the alkali metals

Abstract

In this work, we compiled, evaluated, and selected recommended values for the normal melting points (T m ) and normal boiling points (T b ) of the alkali metals: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). We also compiled and evaluated vapor pressures for lithium and fitted these sets of data in order to both more accurately determine the boiling point and to derive a real gas enthalpy of vaporization (employing a compressibility factor Z). For all values reported prior to 1990, we corrected the values to the International Temperature Scale of 1990 (ITS-90).