Formal Charges

Simple Explanation: 

Formal charges serve as a method to figure out what the most stable structure of a molecule would be. This protocol ensures the accuracy of drawing Lewis structures. 

The formula for calculating the formal charge of an atom in a Lewis structure is: 

FC = V - N - B/2

• FC: Formal Charge 

• V: Valence Electrons 

• N: Non-bonding Electrons (Lone Pairs) 

• B: Bonded Electrons 

A shortcut for this formula would be to replace B/2 with (# of Bonds), as there are two electrons per bond, one from each atom. 

Add the formal charges (FC) of atoms in a molecule together. The closer the sum is to the charge of the actual compound, the more stable the Lewis structure is.