the small first ionization energies of the alkali atoms are reflected in the bond dissociation energies of the gaseous alkali diatomic molecules, which, as table 14.1 shows, range from 25 keal for Li2 to 10.4 keal for Cs2. The energy lowering associated with covalen-bond formation comes from the extra attraction an electron feels when it moves in the electric field of move that one nucleus