二氧化碳的正確化學符號

Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. It is often referred to by its formula CO2. It is present in the Earth's atmosphere at a low concentration of approximately 0.03%-0.06% and is an important greenhouse gas. In its solid state, it is called dry ice. It is a major component of the carbon cycle.

Carbon dioxide
圖片參考：http://upload.wikimedia.org/wikipedia/commons/thumb/4/41/Carbon-dioxide-3D-vdW.png/140px-Carbon-dioxide-3D-vdW.png
Other names Carbonic acid gas,
Carbonic anhydride,
dry ice (solid) Molecular formula CO2 Molar mass 44.0095(14) g/mol Solid state Dry ice, carbonia Appearance colorless gas CAS number [124-38-9]

係CO2，個2字要寫低啲。

喺會考程度，要測試出二氧化碳可以用石灰水(Limewater)。

二氧化碳為一酸性氣體，可溶於水，另外二氧化碳的固體即係乾冰。