AP Chemistry - Michalek
18
Unit 08 Bonding Concepts
Formal Charge –charge assigned to each atom in a molecule
Rules Governing Formal Charge
1. To calculate the formal charge on an atom:
a. Take the sum of the lone pair electrons and .5 the shared electrons.
b. Subtract the number of assigned electrons in valence shell
2. The sum of the formal charges is the charge of the atom or ion.
Example 8.12b
Give possible Lewis Structures for XeO
Which Lewis Structure or structures are most appropriate according to the
3.
formal charge?