Stable Resonance Structures

[Aimee Alvarado 3J]

What are all of the things that we need to take into account before determining which resonance structure is stable or not?

[Alison Perkins 2B]

I know that for resonance structures you must determine which has the most stable formal charge, to ensure that this is the most stable atom. I am not sure of what else.

[MichaelRaad_1F]

I think formal charge is the only way to check which resonance structure is ideal unless the question tells you the determined bond lengths the elements form. You would then need to choose the structure that most accurately has bond lengths similar to the experimentally determined ones.

[Natalie 3k]

As of what we've learned so far I think the biggest thing to look at is the formal charge if the question doesn't give you any more info. The structure with the least number of formal charges is most stable. I also believe that the structure with the least separation of formal charge is more stable as well. There might be more ways in the future but I'm not sure.

[Wasila Sun 2I]

More stable resonance structures occur when the each atom (other than He or H) has a full octet and there is a small number of formal charges. For example, a -1 molecule could have a resonance structure with formal charges of -2 and +1 on their atoms. This molecule has 2 atoms with formal charge, but if we use a resonance structure of the same molecule with only one atom that has a formal charge of -1, then this structure would be the more stable one.