Answer the following question given this paragraph: 

A molecular formula of the compound carbon dioxide is CO 2 . One molecule of carbon dioxide consists of 1 atom of carbon and 2 atoms of oxygen. We can calculate the mass of one molecule of carbon dioxide by adding together the masses of 1 atom of carbon and 2 atoms of oxygen.


Q: One molecule of carbon dioxide consists of 1 atom of carbon and 2 atoms of what element?

 Choices:

- methane

- hydrogen

- nitrogen

- oxygen

A:
oxygen
