That's a great question! When hydrogen burns in air, it reacts primarily with oxygen to form water (H₂O). Here's what happens to the nitrogen:

* Nitrogen is inert: Nitrogen makes up about 78% of the air, but it's relatively unreactive at normal temperatures. It doesn't readily participate in the combustion reaction.

* No direct reaction: The burning hydrogen doesn't directly react with the nitrogen in the air.

* Nitrogen remains: The nitrogen remains in the air, unchanged, after the hydrogen has burned.

In summary, the nitrogen in the air simply acts as a spectator, not participating in the chemical reaction when hydrogen burns.