Step 1: Find valence e- for all atoms. Add them together.
Step2: Find octet e- for each atom and add them together.
Step3: Subtract step 1 total from step 2. Gives you bonding e-.
Step 4: Find number of bonds by diving the number in step 3 by 2(because each bond is made of 2 e-)
12e-/2= 6 bond pairs
Step 5: Find the number of nonbonding (lone pairs) e-. Subtract step 3 number from step 1.
12-12= 0e-=0 lone pairs
Use information from step 4 and 5 to draw the lewis structure.
Lewis dot structure of C2H4
Alternatively a dot method can be used to draw the lewis structure.
Calculate the total valence electrons in the molecule.
Put two carbons in the center and arrange hydrogena toms on the sides.Arrange electrons until both carbons get 8 electrons.