posted by mandy .
Write a Lewis structure of OSF4 in which the formal charges of all atoms are zero
We can't draw pictures on these boards.
Here is a try at it with some comments to help.
OK. Replace each | with two dots (for two electrons). Add two dots left, top, and right side of each F.
Add one more F with two dots between F and S. Then two more dots left, top, and bottom of the F.
Now add an oxygen atom bonded to the Si with 4 dots. Add two dots to top and two more to bottom of oxygen. This will give a formal charge, unless I miscalculated, of zero on F, O, and Si and gives 8 electrons around O and F and 12 around Si. I hope this helps.