Compound reference
Hydrogen fluoride
HF
The chemistry
Fluorine grabs hydrogen with one bond - and hides three lone pairs. The greediest atom you'll meet.
Remember it as…
One bond, three lone pairs on F. Most electronegative atom on the table - H–F is the most polar simple bond there is.
Common mix-up
HF is a WEAK acid in water, not a strong one. The H–F bond is so strong (and F⁻ holds H⁺ so tightly) that the dissociation is incomplete - counterintuitive given fluorine's electronegativity.
Where the name comes from
Fluorine from Latin fluere (to flow) - early metallurgists used fluorspar (CaF₂) as a flux to make ores melt and flow.
Where you meet it
Etches glass; used to make non-stick coatings, refrigerants, and pharmaceuticals; vapor is corrosive enough to dissolve cell membranes on contact.
PubChem facts
- IUPAC name
- fluorane
- Molecular weight
- 20.0064 g/mol
Also known as: hydrofluoric acid (the water solution), hydrofluoride
Handling note
Intensely corrosive and toxic; in water (as hydrofluoric acid) it even attacks glass and penetrates skin to the bone.
BondingMolecular geometry
Chemical data from PubChem (NIH/NCBI)