Final answer:
Step 1 of writing Lewis structures with the octet rule: Determine the total number of valence electrons for the atoms in the molecule.
Step-by-step explanation:
Step 1 of writing Lewis structures with the octet rule involves determining the total number of valence electrons for the atoms in the molecule.
Valence electrons are the electrons in the outermost energy level of an atom and play a crucial role in forming bonds.
The steps are as follows:
Determine the total number of valence electrons:
For main-group elements, the number of valence electrons is equal to the group number. For example:
Group 1 elements have 1 valence electron.
Group 2 elements have 2 valence electrons.
Group 13 elements have 3 valence electrons.
Group 14 elements have 4 valence electrons.
Group 15 elements have 5 valence electrons.
Group 16 elements have 6 valence electrons.
Group 17 elements have 7 valence electrons.
Group 18 elements (noble gases) have 8 valence electrons except for helium, which has 2.
Once you have the total number of valence electrons, you can proceed to distribute them around the atoms in the molecule, following the octet rule and minimizing formal charges.