Answer: carbonate ion < carbon dioxide < carbon monoxide
Explanation: Carbon dioxide (chemical formula CO2) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature, and as the source of available carbon in the carbon cycle, atmospheric CO2 is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (HCO−3), which causes ocean acidification as atmospheric CO2 levels increase. Bond strength depends on the bond order of a bond. The higher the bond order, the greater the bond strength since shorter bonds are stronger than longer bonds. The carbonate ion has a bond order of 1.33, carbon dioxide has a bond order of 2 while carbon monoxide has a bond order of 3. Since the compound with the highest C-O bond order has the strongest C-O bond, then carbon monoxide possesses the strongest C-O bond. It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% by volume (as of May 2022), having risen from pre-industrial levels of 280 ppm. Burning fossil fuels is the primary cause of these increased CO2 concentrations and also the primary cause of climate change.