Up to 90 off textbooks at amazon canada plus free two day shipping for six months when you sign up for amazon prime for students. Approach to chemical bonding molecules formation of covalent bonds can be represented as or cl cl covalent bond between two cl atoms thus when two atoms share one electron pair they ar e said to be jo ined by a single covalent bond in many c ompounds we have multiple bonds between atoms the for mation of multiple bonds envisages sharing of more than one electron pair between two . A key concept in a discussion of chemical bonding is that of the molecule molecules are the smallest units of compounds that can exist one feature of molecules that can be predicted with reasonable success is their shape