Carbon oxides are a group of chemical compounds that contain carbon and oxygen atoms. The two most common carbon oxides are carbon monoxide (CO) and carbon dioxide (CO2).

1. Carbon monoxide (CO):
- Physical state: Carbon monoxide is a colorless, odorless, and tasteless gas at room temperature.
- Density: The density of carbon monoxide is slightly lighter than air.
- Melting and boiling points: Carbon monoxide does not have a specific melting or boiling point because it exists as a gas at normal atmospheric conditions.
- Solubility: Carbon monoxide is sparingly soluble in water.
- Reactivity: Carbon monoxide is highly reactive and can form various compounds with other elements.

2. Carbon dioxide (CO2):
- Physical state: Carbon dioxide is a colorless gas at room temperature.
- Density: The density of carbon dioxide is heavier than air.
- Melting and boiling points: Carbon dioxide does not have a specific melting or boiling point because it exists as a gas at normal atmospheric conditions.
- Solubility: Carbon dioxide is soluble in water, and it forms carbonic acid when dissolved.
- Reactivity: Carbon dioxide is relatively stable and does not readily react with other substances under normal conditions.

Overall, carbon oxides are important in various industrial processes and have significant environmental implications. Carbon monoxide is toxic and can be harmful to human health, while carbon dioxide is a greenhouse gas that contributes to climate change.