in both cases less than the usual octet. The alternative, requiring eight electrons on
the central atom, predicts multiple bonds, with BeF2 analogous to C02 and BF3 analogous
to SOs (Figure 3-7). These structures, however, result in formal charges (2- on Be
and 1 + on F in BeF2, and 1 - on B and I + on the double-bonded F in BF3), which are
unlikely by the usual rules.