Fe2o3
Assuming that you are asking about ferric oxide, its formula is Fe2O3
Fe2O3 or iron(iii) oxide
Ferric Carbonate = Iron (III) carbonate. Fe3+ + 3CO32- ==> Fe2(CO3)3
Oxygen is a chemical element and ferric oxide is a chemical compound: they are not "changes".
There are a number of compounds of iron wuth oxygen, iron(I) oxide, ferrous oxide, FeO iron (II,III) oxide ferric ferrous oxide, Fe3O4 iron(III) oxide, ferric oxide, Fe2O3.
The molecular formula for Ferric Oxide is Fe2O3.
feo3
There are a number of compounds of iron wuth oxygen, iron(I) oxide, ferrous oxide, FeO iron (II,III) oxide ferric ferrous oxide, Fe3O4 iron(III) oxide, ferric oxide, Fe2O3.
The chemical formula for ferric nitrate/ iron nitrate is Fe(NO3)3.
Fe3PO4
FeO for ferrous oxide, ( iron(II) oxide); Fe2O3 for ferric oxide, (iron(III) oxide) and Fe3O4 for ferrous ferric oxide, (iron (II,III) oxide)
The chemical formula for tri ferric tetra oxide is Fe3O4. It consists of 3 iron (Fe) atoms and 4 oxygen (O) atoms. It is also known as magnetite and is a black mineral with magnetic properties.