We saw in thw last chapter how covalent bonds between atoms are described, and we rooked at the valence bond model, wich uses hybrid orbitals to account for the observed shapes of organic molecules. Befor going on to a systematic study of organic chemisty, however, we still need to review afew fundamental topics. In particular. We need to look inore closely at how eiectrons are distributed in covalentbond are at some of the consequences that arise when the electrons in a bornd are not shared equally between atoms.