This two volume set provides a clear understanding of the essence of a metallic liquid's thermophysical properties which is indispensable for improving, or innovating any liquid metal processing operation or product quality. The thermophysical properties of metallic liquids are presented, i.e. liquid metals, semimetals, and semiconductors, analysed in relation to our current understanding of the underlying structure of a metallic liquid on the atomic scale and of the electron configuration of an element. The authors' interdisciplinary approach brings together knowledge from various subject areas including: process metallurgy, materials science, condensed matter physics, chemistry, metrology. They introduce new dimensionless parameters to characterise the atomic states of metallic liquids (i.e. an atom's hardness or softness, its anharmonic motions, and the spatial arrangement of the atoms in a metallic liquid), as revealed through data for the velocity of sound in the metallic liquids. The two new simple parameters, common to all elements, allow for better predictions of several important thermophysical properties of liquid metallic elements.