The atomic symbols of nitrogen and oxygen are n and o, respectively. the chemical formula of a particular substance is no2. which of the following is a correct description of the substance? a. a compound made up of 2 nitrogen atoms and 2 oxygen atoms b. an element made up of 2 nitrogen atoms and 2 oxygen atoms c. a compound made up of 1 nitrogen atom and 2 oxygen atoms d. an element made up of 1 nitrogen atom and 1 oxygen atom