Editing Nitrogen fixation (section)

== Lightning ==
[[File:Lightning Pritzerbe 01 (MK).jpg|thumb|[[Lightning]] heats the air around it in a high-temperature [[Plasma (physics)|plasma]], breaking the bonds of {{chem|N|2}}, starting the formation of [[nitrous acid]] ({{chem|HNO|2}}).]]
Nitrogen can be fixed by [[lightning]] converting nitrogen gas ({{chem|N|2}}) and oxygen gas ({{chem|O|2}}) in the atmosphere into {{NOx}} ([[nitrogen oxides]]). The {{chem|N|2}} molecule is highly stable and nonreactive due to the [[triple bond]] between the nitrogen atoms.<ref name="Tuck-1976">{{Cite journal| vauthors = Tuck AF |date=October 1976 |title=Production of nitrogen oxides by lightning discharges|journal=Quarterly Journal of the Royal Meteorological Society|volume=102|issue=434|pages=749–755|doi=10.1002/qj.49710243404|issn=0035-9009|bibcode=1976QJRMS.102..749T}}</ref> Lightning produces enough energy and heat to break this bond<ref name="Tuck-1976" /> allowing nitrogen atoms to react with oxygen, forming {{chem|NO|x}}. These compounds cannot be used by plants, but as this molecule cools, it reacts with oxygen to form {{chem|NO|2}},<ref>{{cite journal| vauthors = Hill RD |date=August 1979|title=Atmospheric Nitrogen Fixation by Lightning|journal=Journal of the Atmospheric Sciences|volume=37|pages=179–192|doi=10.1175/1520-0469(1980)037<0179:ANFBL>2.0.CO;2|issn=1520-0469|bibcode=1980JAtS...37..179H|doi-access=free}}</ref> which in turn reacts with water to produce {{chem|HNO|2}} ([[nitrous acid]]) or {{chem|HNO|3}} ([[nitric acid]]). When these acids seep into the soil, they make [[nitrate|NO<sub>3</sub><sup>−</sup> (nitrate)]], which is of use to plants.<ref>{{Cite web|url=https://journals.ohiolink.edu/pg_99?126555292207822::NO::P99_ENTITY_ID,P99_ENTITY_TYPE:20567211,MAIN_FILE&cs=38gV8XNFDWVznjRjSa1erAIidpqPJBYgnOix4OM5wvpjv8vJAbG2NGhNYwWAVItkNehLIgXVYuozMCrUrENyuYA|title=Tropospheric Sources of NOx: Lightning And Biology | vauthors = Levin JS |date=1984|access-date=2018-11-29}}</ref><ref name="Tuck-1976" />