Chemical Bonding: SF₄ Lewis Structure

Drawing the Lewis Structure for SF₄

Viewing Notes:

• SF₄ is Lewis structure with Sulfur (S). Remember that Sulfur can hold more than 8 valence electrons. In this structure Sulfur will have ten valence electrons.
• The Lewis structure for SF₄ has 34 valence electrons.
• It's a good idea to check the formal charges for the SF₄ Lewis structure to make sure they are zero.

Transcript: Hi, this is Dr. B. Let's do the SF4 Lewis structure. On the periodic table, 6 valence electrons for Sulfur, 7 for Fluorine but we have 4 Fluorines; for a total of 34 valence electrons. We'll put the S, the least electronegative, at the center. We'll put the Fluorines around it, all four of them. Next, we put bonds between atoms. Each bond, two valence electrons like so. And we've used 2, 4, 6, 8 valence electrons. Let's go around the outside: 10, 12, and 32. We've filled the octets for everything and we have two valence electrons left over. We can put those right here because Sulfur is in period 3 and it can have more than eight valence electrons.

Let's check the formal charges and make sure that this is the best structure for sulfur tetrafluoride. Sulfur has 6 valence electrons if you look at the periodic table. It has 2 of these nonbonding, and a total of 8 bonding valence electrons which we'll divide by 2. That gives us zero. That's the formal charge for Sulfur. For Fluorine on the periodic table, it has 7 valence electrons. It has 6 nonbonding and then two in the bond right here, which we'll divide by 2. Seven minus 6 minus 1 is also zero. All these Fluorines are symmetrical so we only have to do one. Since the formal charges are zero, this is the best structure for SF4.

This is Dr. B. with the Lewis structure for SF4, and thanks for watching.