can you give me a brief idea of what a resonance structure is?

Question

it's not for homework but i am trying to get a better idea of it because i don't really understand it. My teacher just taught us it in class today but to get a better idea of it i looked it up online and everything is so detailed.

I just want to know:
- the basic idea
-and how you draw dot structures of molecules or ions using it

Answer 1

A resonance structure is one of two or more structures whose average is needed to describe the actual compound. These are sometimes called canonical structures, because they are gotten from "classical" Lewis theory. In 1860, August Kekule tried to describe benzene as two compounds, 1,3,5-cyclohexatriene and 2,4,6-cyclohexatriene, as shifting back and forth between one another, so that the compound benzene did not behave like either. In 1930, Fritz Eistert conceived the idea of "resonance," in which the two compounds did not shift back and forth, but that benzene was one molecule whose structure was "fuzzed" between the two. Nowadays we explain benzene by a molecular orbital theory, in which molecules have stable shells of electrons the same as atoms. So the reason that benzene is as it is is that the atomic orbitals of benzene carbon atoms combine to yield molecular orbitals. Benzene happens to have a "magic" number of electrons, the same as helium, neon, or argon. Resonance today is a useful tool to help understand how things really are, for those of us who do not have the computing power of molecular orbital calculations.