Question

What are all resonance structures for SO3?

Answer 1

There are seven resonance structures for `"SO"_3`.

Explanation:

When you draw the Lewis structure, you first get the three structures at the top.

In each of them, `"S"` has a formal charge of +2 and two of the `"O"` atoms have formal charges of -1.

In each of the three structures in the middle, `"S"` has a formal charge of +1 and one of the `"O"` atoms has a formal charge of -1.

In the bottom structure, all atoms have a formal charge of zero.

From the point of view of formal charges, the bottom structure is the most stable structure.