Answer:
Carbon Monoxide
Explanation:
Fossil fuels are hydrocarbons which only contain hydrogen and carbon.
When it is burnt in air, it reacts according to this general equation:
2(CH) + 3O2 >> H2O + CO + CO2
- Carbondioxide
- Carbon Monoxide
- Water
CO because it is the chemical symbol for the element cobalt whereas the rest are compound. H20 is water, CO2 is carbon dioxide and N2 is dinitrogen.