A pi bond is a bond formed by the overlap of orbitals in a side-by-side fashion with the electron density concentrated above and below the plane of the nuclei of the bonding atoms. ... Three sigma bonds are formed from each carbon atom for a total of six sigma bonds total in the molecule.
Fe + O2 → Fe2O3
After balancing the eq.
4Fe + 3O2 → 2Fe2O3
Hope this will help u mate :)
There would be 2 which would be on the oxygen