Exceptions to octet guideline

[Alex Dayrit 3B]

How do we know when a compound is stable?

[Simone Byun 1F]

A compound is most stable when the formal charge is 0. Preferably, the formal charges of all of the atoms will be 0. As the formal charges get further away from 0, the less stable. So if a molecule has an atom with a positive formal charge and a negative formal charge, but with an overall net charge of 0, it is still less stable than a molecule where all atoms have a formal charge of 0.

[Clarence Clavite 2K]

A compound is most stable when the formal charge matches the formal charge of the compound. For example SO4^2-. The formal charge for the overall atom should be 2-. Otherwise the closer to 0 it is, the more stable it is.

[Alejandro Oliva 2F]

The number 0 is apparently a very good indicator of a compound's stability. It's best to have a compound with a total formal charge of 0, however other circumstances may arise where a total formal charge may not be completely 0. Some examples included having a compound with atoms with a negative and positive charge that essentially cancel each other out, therefore achieving a 0 charge. The closer a compound's charge is to 0, the more stable the compound is.

[405716590]

A compound is stable when its individual atoms formal charges are as close to zero as possible

[Rebecca Preusch 2C]

A compound is stable when its formal charge matches its overall charge, often when the formal charge is equal to zero.

[Joseph Liao 3C]

When all atoms' formal charge are as close to zero as possible, that is when the atom is as stable as possible. Remember, formal charge can be calculated with the following formula: FC = (V-(L+S/2))!