Which of the following chemical formulas represents a molecule?

H2 CO2 SiO2 NH3

CO2 is a chemical formula that is representing a molecule.

Explanation:

A chemical formula is used to represent molecules in a particular element. Molecules are basically shown by the symbols present in the periodic table. As we know that CO2 is a chemical formula that is representing a molecule because, there are two elements one is carbon whose symbol is C and another element is oxygen whose symbol is O. So in the chemical formula there one carbon atoms and two oxygen atoms.