For each molecule, draw the Lewis structure that satisfies the octet rule for that molecule and also draw the Lewis structure that minimizes formal charges for the molecule as well. For the Lewis structure that satisfies the octet rule, write oxidation numbers for each atom of the molecule. Write formal charges for each atom of the molecule in the Lewis structure that minimizes formal charges.
a.) Sulfur trioxide, SO3: Satisfy octet rule (with oxidation numbers)
b.) Boron trifluoride, BF3: Minimize formal charges (with formal charges)
Satisfy octet rule (with oxidation numbers)
Minimize formal charges (with formal charges)