Why is there 78% nitrogen in the air, or where does this vast proporton of nitrogen come from?
It’s not so much coming from anywhere as just staying there. Nitrogen is rather unreactive in its normal gaseous form – lightning can combine it with things, but otherwise it does nothing naturally. When you see ‘packed in a protective atmosphere’ on something, it often means nitrogen. The nitrogen cycle is biologically driven http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/NitrogenCycle.html More reactive gases like oxygen and hydrogen will combine with other things and be lost to the atmosphere (apart from carbon dioxide and monoxide). And the least dense gases (hydrogen and helium) will be lost to space. Nitrogen also has low solubility in water, unlike oxygen, and the amount contained in the oceans will be very small. There is quite a lot of oxygen dissolved in the surface waters of the Earth. When you think about it, there’s a heck of a lot of oxygen and hydrogen tied up in all that water as well… Not to mention the amounts tied up in organic matter, where nitrogen is a
