Compound reference
Oxygen
O₂
- Geometry
- linear
- Bond angle
- 180°
The chemistry
A double bond between two oxygens. Each O still keeps two lone pairs. The air you breathe.
Remember it as…
O=O with two lone pairs on each end. Both oxygens "see" 8 electrons. Stable.
Common mix-up
Real O₂ has two unpaired electrons (it's paramagnetic) - the simple Lewis structure with the double bond is a useful HS approximation but doesn't capture that quirk. You'll meet molecular orbital theory in college.
Where the name comes from
Greek oxys (sharp/sour) + genēs (forming) - Lavoisier coined "oxygen" thinking it was the universal acid-former. He was wrong about that, but the name stuck.
Where you meet it
Drives respiration; supports combustion; produced by photosynthesis; reactive enough that life had to evolve mechanisms to handle it without burning itself.
PubChem facts
- IUPAC name
- molecular oxygen
- Molecular weight
- 31.999 g/mol
Also known as: dioxygen
Handling note
Not flammable itself, but a powerful oxidizer that makes fires burn far more fiercely, so it is kept away from flames and oils.
BondingMolecular geometry
Chemical data from PubChem (NIH/NCBI)