What is the molecular formula for carbon dioxide?

The molecular formula for carbon dioxide is CO2. This formula indicates that one molecule of carbon dioxide consists of one carbon (C) atom and two oxygen (O) atoms.

To understand this, carbon dioxide is a well-known compound where the carbon atom forms a double bond with each of the two oxygen atoms. This combination leads to the characteristic properties of carbon dioxide, such as its role in photosynthesis and its presence in the Earth's atmosphere.

The other options do not correspond to carbon dioxide. C2O2 would imply a compound with two carbon atoms and two oxygen atoms, which is actually a different compound known as carbon suboxide. CO represents carbon monoxide, which consists of one carbon atom and one oxygen atom. Finally, C3O2 suggests a compound with three carbon atoms and two oxygen atoms, which does not represent carbon dioxide. Thus, the correct and most recognized molecular formula for carbon dioxide remains CO2.