Doubled stuff
Hydrogen
Nitrogen
Oxygen
Fluorine Iodine Bromine Astatine (At) Chlorine FIBAC
Phosphorus
P4
Sulphur
S8
Ozone
O3
Methane
CH4
Methanol
CH3OH
Propane
C3H8
water
H2O
Sucrose
C12H22O11
ethanol
C2H5OH
ammonia
NH3
glucose
C6H12O6
Hydrogen peroxide
H2O2