Bonding orbitals, chemical conventions

Figure 3.11 Conventional representations of the shapes of the p orbitals. They are used as approximate representations of both ip and tp2. The sign of tp is indicated by the shading. (Reproduced with permission from and M. J. Winter, Chemical Bonding, 1994, Oxford University Press, Oxford.)...

In writing the conventional Lewis structures for molecules, we assume that a covalent chemical bond between two atoms involves sharing of a pair of electrons, one from each atom. Figure 6-5 shows how atomic orbitals can be considered to be used in bond formation. Here, we postulate that a single bond is formed by the pulling together of two atomic nuclei by attractive forces exerted by the nuclei for the two paired electrons in overlapping atomic orbitals. 

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