Compound reference
Sulfur hexafluoride
SF₆
The chemistry
Six bonds around one sulfur. The octet rule is for period-2 atoms; period-3+ can hold more. Octahedral - every angle is 90°.
Remember it as…
Six F's at the corners of an octahedron, S in the middle. 12 electrons on S - expanded octet, perfectly stable.
Common mix-up
The octet rule isn't a law. It's a pattern that holds for period-2 elements (their outer shell can only fit 8). Period-3+ elements can use d-orbitals (or 3-center bonds in the modern picture) to host more - SF₆'s 12 electrons are not exotic.
Where the name comes from
Hexa- (Greek for six) + fluoride. The naming is purely descriptive - six fluorines.
Where you meet it
Inert insulator inside high-voltage electrical equipment; about 23,500× stronger than CO₂ as a greenhouse gas over 100 years; lasts millennia in the atmosphere.
PubChem facts
- IUPAC name
- hexafluoro-lambda6-sulfane
- Molecular weight
- 146.06 g/mol
Also known as: sulphur hexafluoride
Handling note
The mildest one here: a dense, unreactive gas whose main risk is asphyxiation if it displaces air.
BondingMolecular geometry
Chemical data from PubChem (NIH/NCBI)