Step 1: Find valence e- for all atoms. Add them together.
Step2: Find octet e- for each atom and add them together.
Step3: Gives you bonding e-. Subtract step 1 total from step 2
Step 4: Find number of bonds by diving the number in step 3 by 2(because each bond is made of 2 e-)
4e-/2= 2 bond pairs
Step 5: Find the number of nonbonding (lone pairs) e-. Subtract step 3 number from step 1.
8-4= 4e-=2 lone pair
Use information from step 4 and 5 to draw the lewis structure.
Oxygen goes in the centre.
Lewis dot structure of H2O
Alternatively a dot method can be used to draw the lewis structure.
Calculate the total valence electrons in the molecule.
Put oxygen in center and arrange hydrogen atoms on the sides.put a pair of electrons connecting hydrogen with oxygen and the remaining four electrons on oxygen..