the charge assigned to an atom in a molecule or polyatomic ion derived from a specific set of rules

the magnitude and sign of the charge on an atom

The charge on an atom in its Lewis structure. Formal charge is calculated by dividing the electrons in each covalent bond between the atoms in the bond, and then comparing the number of electrons that can be formally assigned to each atom with the number of electrons on a neutral atom of the element.

In the Lewis representation of molecular structure, the formal charge, FC, on an atom may be defined as FC = N(electrons on parent atom) -N(unshared electrons) -0.5N(shared electrons).

an apparent charge on an atom in a molecule as a result of unequal contributions of electrons to covalent bond electron pairs