Chemical Bonding: NF₃ Lewis Structure

Drawing the Lewis Structure for NF₃

Viewing Notes:

• NF₃ (Nitrogen trifluoride) is very similar to the NCl₃ and NH₃ Lewis structure.
• In the NF₃ Lewis structure (and all structures) hydrogen goes on the outside.
• Hydrogen only needs two valence electrons to have a full outer shell.
• In the Lewis structure for NF₃ there are a total of 8 valence electrons.

Transcript: Hi, this is Dr. B. We're going to do the Lewis structure for NF3, nitrogen trifluoride. On the periodic table, Nitrogen is in group 5 or 15, so it has 5 valence electrons; and then Fluorine is in group 7 or 17, it has 7. We've got three Fluorines, though, so let's multiply that by 3. That equals, 21 plus 5, is 26 valence electrons. Nitrogen is the least electronegative, so that's going to go in the center here, and then we'll put the F's, those Fluorines around there, and we have three of them. OK, so at this point we've got 26 valence electrons to work with. Let's first put them between atoms to form that chemical bond there. So 2, 4, 6; and spread them around the outside now.

So we have 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, and we'll put the last two here, 26, which is what we had to work with, to give Nitrogen an octet. Let's check and see if everything has 8 valence electrons, or an octet. Fluorine has 8, this Fluorine has 8, and then this Fluorine right down here, as well, has 8. Their outer shells are full. And then Nitrogen, well, it has eight, too. So that's the correct valence electron count for each of these, so our Lewis structure is done. And we could also draw it as a structural formula, and that would look like this right here.

That is the Lewis structure for NF3. This is Dr. B., and thanks for watching.