B2O3: Note that the prefix "di-" means two and the prefix "tri-" means three.
The compound Br2O3 is called bromine trioxide. It is a chemical compound formed from bromine and oxygen atoms.
Xenon Trioxide
The compound with the formula SO3 is called sulfur trioxide.
The compound with the formula S2O3 is called disulfur trioxide.
Formula: Br2(L)
Dibromine trioxide is not a compound. Bromine forms oxides like bromine dioxide (BrO2) and bromine pentoxide (Br2O5) but not dibromine trioxide.
The chemical formula for dinitrogen trioxide is N2O3.
SO3 is the chemical formula for sulfur trioxide.
The chemical formula for Disilicon trioxide is Si2O3.
Formula: SO3
The formula for xenon trioxide is XeO3.
Formula: XeO3
Formula: SO3
Formula: B2O3
The chemical formula for tellurium trioxide is TeO3.
If Trioxide refers to Ozonide ion, the formula is O3-
Arsenic trioxide refers to Diarsenic trioxide = As2O3 . It is not to be confused as AsO3 which does not exists.