Octet rule summary

In summary, ionic bonds form when there is a transfer of electrons between atoms of different elements. The result of this transfer produces oppositely charged ions. The ions produced generally obtain the valence electron configuration of noble gases, that is, conform to the octet rule. The oppositely charged ions produced are held together by electrostatic attraction. This attractive force is the ionic bond. 

In summary, sometimes we need double or triple bonds to satisfy the octet rule. Writing Lewis stmctures is a trial-and-error process. Start with single bonds between the bonded atoms, and add multiple bonds as needed. 

As depicted in Figure 2.1 and outlined in the Summary of Chapter 2, viable bonding theories started to emerge from the quantum-mechanical model of the atom in the 1920s. G. N. Lewis proposed his now familiar electron-dot diagrams and octet rule for simple compounds in the early 1920s, and by the end of the decade, Nevil Sidgwick applied these ideas to coordination compounds. It was he who first proposed the idea of the coordinate-covalent bond referred to in earlier chapters. 

In Summary Some molecules cannot be described accurately by one Lewis structure but exist as hybrids of several resonance forms. To find the most important resonance contributor, consider the octet rule, make sure that there is a minimum of charge separation, and place on the relatively more electronegative atoms as much negative and as little positive charge as possible. 

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