1. 4 Step Process: Drawing Lewis Dot Structures
Steps for writing Lewis structures:
Key considerations:
The octet rule
An atom’s tendency to attract other electrons (electronegativity).
Step 1: Arrange atoms
Find the central atom and place remaining atoms around it.
The central atom is generally the atom with the lower
electronegativity (EN).
Step 2: Add up valence electrons of all the atoms
If the molecule has a negative charge add additional electrons, (i.e.
-1 charge = 1 added electron; -2 charge – 2 added electrons)
If the molecule has a positive charge subtract electrons, (i.e. +1
charge = 1 added electron; +2 = 2 added electrons)
Step 3: Draw single bonds
Draw a single bond between central atom and surrounding atoms.
For each single bond subtract 2 electrons from the total number of
valence electrons (from step 2)
Step 4: Deal out remaining electrons.
Distribute remaining electrons in pairs’
Start with the atom with the largest electronegativity
Ensure the octet rule is satisfied
Any remaining atoms are placed around the central atom.