The chemical formula for nitrogen and oxygen depends on what specific compound you're talking about. Here are some common examples:

* Nitrogen gas: N₂

* Oxygen gas: O₂

* Nitrous oxide (laughing gas): N₂O

* Nitrogen dioxide: NO₂

* Nitric oxide: NO

* Nitrogen monoxide: NO

* Nitrous acid: HNO₂

* Nitric acid: HNO₃

Please specify which compound you are interested in, and I can give you the correct chemical formula.