CO2
(CO20101-2)

Carbon dioxide
(
chemical
formula
CO2)
is a naturally occurring
chemical compound composed
of 2
oxygen

atoms
each covalently
double bonded to a single
carbon atom. It is a gas
at
standard temperature and pressure
and exists in
Earth's atmosphere in this
state, as a
trace gas at a
concentration of 0.039 per cent by volume.