State the oxidation number charge of the atom indicated in this molecule marked in black bold.
1) CO2
In the unbalanced redox reaction below draw arrows which are in black bold as well as write the subsequent abbreviations "O" for oxidized atom, "R" for reduced atom, "OA" for atom that serves as the oxidizing agent as well as "RA" for the atom that serves as the reducing agent.
2) CrCl6 + PbO yeilds CrO2 + PbCl4