What is Formal Charge?

Formal charge is the charge that an atom would have regardless of electronegativity if all bonding electrons were distributed evenly amongst them. It refer to the charge that the particular atom has in any molecule. It is the parameter that helps in calculating the locations of electrons in a molecule and to define the Lewis structure correctly.

The formal charge helps in finding out the most stable Lewis structure by minimizing the charges on the atoms, thus, the structure with stable atoms is selected. Formal charge can be positive, negative, or zero.

Note: Formal charges are hypothetical charges and do not represent the actual charge distribution in a molecule. They just provide valuable insights into the electronic structure and stability of molecules.

Formal Charge Definition

Formal charge is defined as the difference between the number of electrons assigned to that atom in Lewis structure and its valence electron in its elemental state.

Formal charge also determines whether an atom has more protons (positive charge) or electrons (negative charge).

Formal Charge Formula

The formula for calculating formal charge is:

FC = V – (N + B/2)

Where:

• V is the valence electrons of the neutral atom,
• N is the non-bonding valence electrons, and
• B is the total shared electrons.

Formal charge is a chemical measurement used to understand the way electrons are allocated throughout the molecule or the ion. Each atom in the molecule or ion has a specific charge assigned to it, helping us understand how electrons are distributed around the atom.

In this article, we will explore what is a formal charge, how to calculate a formal charge, importance of formal charge along with a few examples based on it.