The isothermal bulk modulus and surface tension of liquid metals at the melting point correlate better with the quantities characterizing the complete breaking of interatomic bonds, i.e., with the cohesive energy Ecoh, evaporation enthalpy ΔHb and thermal energy at the boiling point RTb, than with the melting enthalpy ΔHm and thermal energy at the melting point RTm. It is shown that the decomposition of liquid metals to the monatomic gas occurs when the distance between atoms increases on average by 50% compared to the melting point. The isothermal bulk modulus and surface tension at melting point increase with decreasing atomic size. The average energy of atoms in the surface layer of liquid metals at the melting point is approximately 9% of the energy in the atomic layer inside the liquid.