Compound reference
Carbon dioxide
CO₂
The chemistry
Two double bonds + zero lone pairs on C give a linear shape. The two C=O dipoles point opposite, so the molecule is non-polar overall - even though each bond is polar.
Remember it as…
O=C=O. Two regions of electron density on carbon, no lone pairs - a perfectly straight line.
Common mix-up
Polar bonds don't always make a polar molecule. CO₂ has two strongly polar C=O bonds, but the linear geometry makes the dipoles cancel exactly. Symmetry beats bond polarity.
Where the name comes from
"Carbon" from Latin carbo (charcoal); "dioxide" = two oxygens. The "di-" prefix is Greek dis (twice).
Where you meet it
Exhaled with every breath, drives photosynthesis, freezes to dry ice without becoming liquid first - a workhorse of the carbon cycle.
PubChem facts
- IUPAC name
- carbon dioxide
- Molecular weight
- 44.009 g/mol
Also known as: carbonic anhydride, carbonic acid gas
Handling note
Not toxic in small amounts, but as a heavy gas it can build up and push out breathable air in a closed space.
BondingMolecular geometry
Chemical data from PubChem (NIH/NCBI)