The Lewis structure for hydrogen fluoride (HF) can be drawn by considering the number of valence electrons available. In HF, hydrogen has 1 valence electron, and fluorine has 7 valence electrons, giving a total of 8 valence electrons to consider.
To draw the Lewis structure:
- Place the hydrogen atom (H) and the fluorine atom (F) next to each other.
- Since hydrogen can only make one bond, connect H and F with a single bond, which accounts for 2 valence electrons.
- This leaves us with 6 valence electrons from fluorine. We can place these remaining electrons around the fluorine atom to complete its octet, leading us to depict 3 lone pairs around F.
The resulting Lewis structure looks like this:
H - F: (with 3 lone pairs around F)
In terms of molecular geometry, HF is a simple diatomic molecule. Therefore, it is linear in shape. There are no angles to consider since there are only two atoms.
Now, regarding polarity: HF is a polar molecule. This is due to the difference in electronegativity between hydrogen and fluorine. Fluorine is much more electronegative than hydrogen, which leads to a partial negative charge on fluorine and a partial positive charge on hydrogen. This difference creates a dipole moment, confirming that HF is polar.