Answer/Explanation:
CO and CO2 are both carbon poisoning. They both are odorless, colorless, and potentially deadly. But the chemical difference(extra oxygen molecule) causes it to be a different substance. CO is carbon monoxide while CO2 is carbon dioxide. CO2 is common because it is what we exhale after a breath, it is used to keep plants alive. On the other hand CO is caused by gas emissions and lack of oxygen. They may sound the same but they are just two different molecules containing the same types of atoms.