The elements in the compound are represented by their chemical symbols in a chemical formula and ratios of different elements are represented as subscripts on each chemical symbol.
The nitrogen and oxygen forms different compounds.
[tex]NO[/tex]
[tex]N_2O[/tex]
[tex]NO_2[/tex]
[tex]N_2O_5[/tex]
[tex]N_2O_4[/tex]