ELi5: Where did all the nitrogen in the air come from?

Question

ELi5: Where did all the nitrogen in the air come from?

In: Earth Science

Answer 1

Ultimately? Fusion. The entire solar system was formed from the fusion reactions occurring in the first stars, combining the original hydrogen and helium until eventually going supernova, releasing heavier elements out of their gravity well.

So Earth always had that nitrogen from its formation.