Energies of valence states of atoms in halides

Variation in energy of valence states (E) in alternate-valence series involving the elements of the groups 5-7 of the periodic system has been first considered on the basis of review of experimental data on the formation heat of gaseous halides (Be, Sr, B, W fluorides and Mo, V, Ta, Nb chlorides). The dependences are compared with calculation data for E. The principal reasons of non-monotonous variation of E in alternate-valence series of multivalence metals are discussed