Editing Nitrogen (section)

===Liquid===
{{main |Liquid nitrogen}}
[[File:Nitrogen.ogv|thumb|Air balloon submerged in liquid nitrogen]]
Liquid nitrogen is a [[cryogen|cryogenic liquid]] which looks like [[water]]. When insulated in proper containers such as [[dewar flask]]s, it can be transported and stored with a low rate of [[evaporation|evaporative loss]].<ref>{{Cite journal|doi=10.1007/BF01136404|title=Vessels for the storage and transport of liquid oxygen and nitrogen|author=Kaganer, M. G.|author2=Kozheurov, V.|author3=Levina, Zh. L.|name-list-style=amp|journal=Chemical and Petroleum Engineering|volume=3|issue=12|year=1967|pages=918–22|bibcode=1967CPE.....3..918K |s2cid=96762552}}</ref>
[[File:A cylinder container, containing liquid nitrogen.jpg|thumb|A container vehicle carrying liquid nitrogen]]

Like [[dry ice]], the main use of liquid nitrogen is for cooling to low temperatures. It is used in the [[cryopreservation]] of biological materials such as blood and reproductive cells ([[sperm]] and [[ovum|eggs]]). It is used in [[cryotherapy]] to remove cysts and warts on the skin by freezing them.<ref>{{cite journal|pmid=11359389|volume=144|issue=5|title=Liquid nitrogen cryotherapy of common warts: cryo-spray vs. cotton wool bud|date=May 2001|journal=Br. J. Dermatol.|pages=1006–09|author=Ahmed I|author2=Agarwal S|author3=Ilchyshyn A|author4=Charles-Holmes S|author5=Berth-Jones J|doi=10.1046/j.1365-2133.2001.04190.x|s2cid=221325640}}</ref> It is used in laboratory [[cold trap]]s, and in [[cryopump]]s to obtain lower pressures in [[vacuum pump]]ed systems. It is used to cool heat-sensitive electronics such as [[infrared detector]]s and [[X-ray detector]]s. Other uses include freeze-grinding and machining materials that are soft or rubbery at room temperature, shrink-fitting and assembling engineering components, and more generally to attain very low temperatures where necessary. Because of its low cost, liquid nitrogen is often used for cooling even when such low temperatures are not strictly necessary, such as refrigeration of food, [[freeze-branding]] livestock, freezing pipes to halt flow when valves are not present, and consolidating unstable soil by freezing whenever excavation is going on underneath.<ref name="Greenwood409" />