The variation of known dissociation energies of the transition metal diatomics across the Periodic Table is rather irregular in a manner similar to the irregular variation of the enthalpies of sublimation of the bulk metals. This has suggested that the valence-bond model used for bulk metallic systems might be applicable to the gaseous diatomic molecules as well as to the various clusters intermediate between the bulk and the diatomic molecules. The available dissociation energies were converted to valence-state bonding energies, considering various degrees of promotion to optimize the bonding. It was found that the model used for the bulk metals was applicable to the diatomic molecules. The degree of promotion of electrons to increase the number of bonding electrons is smaller than for the bulk, but the trends in bonding energy parallel the behaviour found for the bulk metals. Thus using the established trends in bonding energies for the bulk elements, it was possible to calculate all unknown dissociation energies to provide a complete table of dissociation energies for all M₂ molecules from H₂ to Lr₂. The details of the calculations and final values are presented.