Rules, of resonance

In this chapter, you will learn the tools that you need to draw resonance structures with proficiency. I cannot adequately stress the importance of this skill. Resonance is the one topic that permeates the entire subject matter from start to finish. It finds its way into every chapter, into every reaction, and into your nightmares if you do not master the rules of resonance. You cannot get an A in this class without mastering resonance. So what is resonance And why do we need it ... 

Everyone receives an introduction to the basic concepts of resonance in Organic Chemistry I. Organic Chemistry II requires an extension of the basic rules of resonance to other systems. In addition to constructing reasonable resonance structures, you also need to understand which structures cire more stable. 

D is correct. Moving atoms is a violation of the rules of resonance. The actual molecule is always at a lower energy level than any of its resonance structures. Although A and B are true, they don t answer the question. Notice that A and B say the same thing. This is a good indicator that they are both wrong. 

It is important to know nuclear level densities in order to check the sum rules of resonance theories (Sect. 9). A summary of available information is... 

Key Ideas are highlighted. These include topics pivotal to students development in organic chemistry, such as Proposing a Mechanism for a Reaction and the Rules of Resonance. These Key Ideas are further reinforced in end-of-chapter problems marked with a A icon. 

---