Drawing the Lewis Structure for BF4-

Viewing Notes:

  • The BF4- Lewis structure has a total of 32 valence electrons. This includes the electron represented by the negative charge in BF4-.
  • You need to put brackets around the BF4- Lewis structure as well as a negative charge to show that the structure is a negative ion.
  • If you calculate the formal charges for BF4- you'll find that the Boron has a -1 charge and the Fluorine atoms each have a formal charge of zero. This gives the entire structure a -1 charge (remember it's BF4-).

Transcript: Hi, this is Dr. B. Let's do the BF4- Lewis structure. BF4- has 32 valence electrons. We'll put the Boron in the center, it's the least electronegative; and the Fluorines on the outside. Put bonds between the Boron and the Fluorines. Each bond is two valence electrons. We've used eight. And then around the outer atoms, 2, so we have 8, 10, 12, and 32. If you check the formal charges, you'll see that the Boron has a charge of -1 and the Fluorines all have formal charges of zero. Because of that, we'll want to put brackets around the BF4- ion, because it is an ion and we want to show people it has a negative one charge.

And that's the Lewis structure for BF4-. We've used all 32 valence electrons. Our formal charges make sense, they add up to minus one. That's all you've got to do. This is Dr. B., and thanks for watching.