Kelter Strategy for Writing
Lewis Structures
1. Total # valence electrons in the system
CO3-2
C = 4 O = 6 x 3 (18) 4+18 =22
Don’t forget the charge it also accounts for
electrons
22+2=24
2. # of electrons to make everyone
happy.
# of atoms times 8 (What are the
exceptions?)
4 x 8 = 32
3. # of bonds
Step 2 – Step 1 divided by 2 (Shared
electrons)
32 – 24 = 8/2 = 4
4. Draw structure
O
O
O
..
..
..
C
Denotes a pair
of electrons