Question

give me the correct structure of sulphur trioxide SO3?

Does it trimerises itself in its structure (S3O9) or it remains as SO3 only?

Answer 1

For the SO3 Lewis structure we first count the valence electrons for the SO3 molecule using the periodic table. Once we know how many valence electrons there are in SO3 we can distribute them around the central atom and attempt to fill the outer shells of each atom. When we are done adding valence electrons we check each atom to see if it has an octet (full outer shell). We also need to check to make sure we only used the number of available valence electrons we calculated earlier. There are a total of 24 valence electrons for the SO3 Lewis structure. The Lewis structure for SO3 is a bit tougher since you have to take formal charges into account to find the best Lewis structure for the molecule. Remember that sulfur can have more than 8 valence electrons since it is in Period Three on the periodic table.