Exceptions to the Octet Rule • Atoms with fewer than 4 electrons sharing them to form covalent bonds like Be and B in BeCl2 and BCl3 .. .. : Cl . .Be. .Cl: .. .. o Certains atoms in the higher periods like Phosphorus in PCl5 and S in SF6 have 5 and 6 bonding pairs Cl Cl F P Cl F S Cl F Cl F F F o An odd number in the total valence electrons like NO2 with a total valence electrons of 5 + ( 6 x2) = 17 .. . .. O = N –O: N did not follow the octet. .. ..