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

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

In: Earth Science

Originally it comes from a supernova it is a relatively light element and one of the more common elements in the universe.

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.

Nitrogen was just part of the primordial gas and dust left in the nebulae that formed the solar system, the same as all the other elements. The difference is that Nitrogen forms a particularly stable diatomic molecule, so when you have a bunch of nitrogen in any form, it will tend toward reacting to maximize the amount of N2.

Then, once you have that, it floats above most of the rest of the Earth due to it being a gas.