Drawing the Lewis Structure for HF

Viewing Notes:

  • HF is very similar to HF and HCl. Hydrogen has 1 valence electron and Fluorine (in Group 7 with F and Cl) has 7 valence electrons.
  • With the Lewis Structure for HF remember that Hydrogen only needs 2 valence electrons to have a full outer shell.
  • Be sure that you don't use more than the 8 valence electrons available.

Transcript: Hi, this is Dr. B. We're going to do the Lewis structure for HF, hydrofluoric acid. This stuff melts glass. Very cool. Start out looking at the periodic table. Hydrogen is in group 1 so it has 1 valence electron, and then Fluorine is in group 7, sometimes called 17, so it has 7 valence electrons. One plus 7 equals 8. So we have a total of 8 valence electrons to work with. So we could start by drawing the H and then the F, and we'll put electrons (we have 8); let's start putting two here, bond the H and the F together. And that actually fills the outer shell of Hydrogen there, which only needs two.

So we have 8 total, we've used 2, 4, 6, 8. And it looks like the Fluorine has 2, 4, 6, 8 and the Hydrogen has two. We've satisfied the octet, and 2, 4, 6, 8; we've used all 8 valence electrons. You could also write this as a structural formula that would look like this right here, where these two electrons would be represented by that straight line there, that single bond.

That's the Lewis structure for hydrofluoric acid. This is Dr. B., and thanks for watching.