Isotopes of nitrogen

{{Short description|none}} {{Infobox nitrogen isotopes}} Natural nitrogen (₇N) consists of two stable isotopes: the vast majority (99.62%) of naturally occurring nitrogen is nitrogen-14, with the remainder (0.38%) being nitrogen-15. Thirteen radioisotopes are also known, with atomic masses ranging from 9 to 23, along with three nuclear isomers. All of these radioisotopes are short-lived, the longest-lived being ¹³N with a half-life of 9.965 minutes. All of the others have half-lives shorter than ten seconds. Isotopes lighter than the stable ones generally decay to isotopes of carbon, and those heavier beta decay to isotopes of oxygen.

Nitrogen-13 is a positron emitter and one of the main isotopes used in medical PET scans.

==List of isotopes== {{Anchor|Nitrogen-24}}

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{{Isotopes table | symbol = N | refs = NUBASE2020, AME2020 II, IsotopeFRIB, IsomerFRIB<!-- was updated as of 2021-12-31) --> | notes = m, resonance, unc(), mass#, spin(), spin#, daughter-st, p, n, IT, discoveryname }} |-id=Nitrogen-9 | {{SimpleNuclide|Nitrogen|9}}<ref name="Cho-2023">{{cite news |url=https://www.science.org/content/article/fleeting-form-nitrogen-stretches-nuclear-theory-its-limits |title=Fleeting form of nitrogen stretches nuclear theory to its limits |last=Cho |first=Adrian |website=science.org |date=25 September 2023 |access-date=27 September 2023}}</ref> | style="text-align:right" | 7 | style="text-align:right" | 2 | | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/9.pdf 2023] | <1&nbsp;as<ref name="Cho-2023"/> | p{{refn|group=n|Decays by proton emission to {{SimpleNuclide|Carbon|8}}, which immediately emits two protons to form {{SimpleNuclide|Beryllium|6}}, which in turn emits two protons to form stable {{SimpleNuclide|Helium|4}}<ref name="Cho-2023"/>}} | {{SimpleNuclide|Carbon|8}} | | | |-id=Nitrogen-10 | {{SimpleNuclide|Nitrogen|10}} | style="text-align:right" | 7 | style="text-align:right" | 3 | {{val|10.04165|(43)}} | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/10.pdf 2002] | {{val|143|(36)|u=ys}} | p ? | {{SimpleNuclide|Carbon|9}} ? | 1−, 2− | | |-id=Nitrogen-11 | {{SimpleNuclide|Nitrogen|11}} | style="text-align:right" | 7 | style="text-align:right" | 4 | {{val|11.026158|(5)}} | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/11.pdf 1974] | {{val|585|(7)|u=ys}}<br/>[{{val|780.0|(9.3)|u=keV}}] | p | {{SimpleNuclide|Carbon|10}} | 1/2+ | | <!--|-id=Nitrogen-11m | style="text-indent:1em" | {{SimpleNuclide|Nitrogen|11m}} | colspan="3" style="text-indent:2em" | {{val|740|(60)|u=keV}} | {{val|690|(80)|u=ys}} | p | | 1/2− | |--> |-id=Nitrogen-12 | rowspan=2|{{SimpleNuclide|Nitrogen|12}} | rowspan=2 style="text-align:right" | 7 | rowspan=2 style="text-align:right" | 5 | rowspan=2|{{val|12.0186132|(11)}} | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/12.pdf 1949] | rowspan=2|{{val|11.000|(16)|u=ms}} | β⁺ ({{val|98.07|(4)|u=%}}) | '''{{SimpleNuclide|Carbon|12}}''' | rowspan=2|1+ | rowspan=2| | rowspan=2| |- | β⁺α ({{val|1.93|(4)|u=%}}) | {{SimpleNuclide|Beryllium|8}}<ref group="n">Immediately decays into two alpha particles for a net reaction of ¹²N → 3 '''⁴He''' + e⁺.</ref> |- | {{SimpleNuclide|Nitrogen|13}} | style="text-align:right" | 7 | style="text-align:right" | 6 | {{val|13.00573861|(29)}} | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/13.pdf 1934] | {{val|9.965|(4)|u=min}} | β⁺ | '''{{SimpleNuclide|Carbon|13}}''' | 1/2− | trace | |- | {{SimpleNuclide|Nitrogen|14}} | style="text-align:right" | 7 | style="text-align:right" | 7 | {{val|14.003074004251|(241)}} | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/14.pdf 1920] | colspan=3 align=center|'''Stable''' | 1+ | [{{val|0.99578}}, {{val|0.99663}}]<ref name="CIAAWnitrogen" /> | <!--|-id=Nitrogen-14m | style="text-indent:1em" | {{SimpleNuclide|Nitrogen|14m}} | colspan="3" style="text-indent:2em" | {{val|2312.590|(10)|u=keV}} | | IT | '''{{SimpleNuclide|Nitrogen|14}}''' | 0+ | |--> |- | {{SimpleNuclide|Nitrogen|15}} | style="text-align:right" | 7 | style="text-align:right" | 8 | {{val|15.000108898266|(625)}} | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/15.pdf 1929] | colspan=3 align=center|'''Stable''' | 1/2− | [{{val|0.00337}}, {{val|0.00422}}]<ref name="CIAAWnitrogen" /> | |- | rowspan=2|{{SimpleNuclide|Nitrogen|16}} | rowspan=2 style="text-align:right" | 7 | rowspan=2 style="text-align:right" | 9 | rowspan=2|{{val|16.0061019|(25)}} | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/16.pdf 1933] | rowspan=2|{{val|7.13|(2)|u=s}} | β⁻ ({{val|99.99846|(5)|u=%}}) | '''{{SimpleNuclide|Oxygen|16}}''' | rowspan=2|2− | rowspan=2| | rowspan=2| |- | β⁻α ({{val|0.00154|(5)|u=%}}) | '''{{SimpleNuclide|Carbon|12}}''' |-id=Nitrogen-16m | rowspan=2 style="text-indent:1em" | {{SimpleNuclide|Nitrogen|16m}} | rowspan=2 colspan="3" style="text-indent:2em" |{{val|120.42|(12)|u=keV}} | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/7/16N-1.pdf 1957] | rowspan=2|{{val|5.25|(6)|u=µs}} | IT ({{val|99.999611|(25)|u=%}}) | {{SimpleNuclide|Nitrogen|16}} | rowspan=2|0− | rowspan=2| | rowspan=2| |- | β⁻ ({{val|0.000389|(25)|u=%}}) | '''{{SimpleNuclide|Oxygen|16}}''' |-id=Nitrogen-17 | rowspan=3|¹⁷N | rowspan=3 style="text-align:right" | 7 | rowspan=3 style="text-align:right" | 10 | rowspan=3|{{val|17.008449|(16)}} | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/17.pdf 1949] | rowspan=3|{{val|4.173|(4)|u=s}} | β⁻n ({{val|95.1|(7)|u=%}}) | '''{{SimpleNuclide|Oxygen|16}}''' | rowspan=3|1/2− | rowspan=3| | rowspan=3| |- | β⁻ ({{val|4.9|(7)|u=%}}) | '''{{SimpleNuclide|Oxygen|17}}''' |- | β⁻α ({{val|0.0025|(4)|u=%}}) | '''{{SimpleNuclide|Carbon|13}}''' |-id=Nitrogen-18 | rowspan=4|{{SimpleNuclide|Nitrogen|18}} | rowspan=4 style="text-align:right" | 7 | rowspan=4 style="text-align:right" | 11 | rowspan=4|{{val|18.014078|(20)}} | rowspan=4 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/18.pdf 1964] | rowspan=4|{{val|619.2|(1.9)|u=ms}} | β⁻ ({{val|80.8|(1.6)|u=%}}) | '''{{SimpleNuclide|Oxygen|18}}''' | rowspan=4|1− | rowspan=4| | rowspan=4| |- | β⁻α ({{val|12.2|(6)|u=%}}) | {{SimpleNuclide|Carbon|14}} |- | β⁻n ({{val|7.0|(1.5)|u=%}}) | '''{{SimpleNuclide|Oxygen|17}}''' |- | β⁻2n ? | '''{{SimpleNuclide|Oxygen|16}}''' ? |-id=Nitrogen-19 | rowspan=2|{{SimpleNuclide|Nitrogen|19}} | rowspan=2 style="text-align:right" | 7 | rowspan=2 style="text-align:right" | 12 | rowspan=2|{{val|19.017022|(18)}} | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/19.pdf 1968] | rowspan=2|{{val|336|(3)|u=ms}} | β⁻ ({{val|58.2|(9)|u=%}}) | {{SimpleNuclide|Oxygen|19}} | rowspan=2|1/2− | rowspan=2| | rowspan=2| |- | β⁻n ({{val|41.8|(9)|u=%}}) | '''{{SimpleNuclide|Oxygen|18}}''' |-id=Nitrogen-20 | rowspan=3|{{SimpleNuclide|Nitrogen|20}} | rowspan=3 style="text-align:right" | 7 | rowspan=3 style="text-align:right" | 13 | rowspan=3|{{val|20.023370|(80)}} | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/20.pdf 1969] | rowspan=3|{{val|136|(3)|u=ms}} | β⁻ ({{val|57.1|(1.4)|u=%}}) | {{SimpleNuclide|Oxygen|20}} | rowspan=3|(2−) | rowspan=3| | rowspan=3| |- | β⁻n ({{val|42.9|(1.4)|u=%}}) | {{SimpleNuclide|Oxygen|19}} |- | β⁻2n ? | '''{{SimpleNuclide|Oxygen|18}}''' ? |-id=Nitrogen-21 | rowspan=3|{{SimpleNuclide|Nitrogen|21}} | rowspan=3 style="text-align:right" | 7 | rowspan=3 style="text-align:right" | 14 | rowspan=3|{{val|21.02709|(14)}} | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/21.pdf 1970] | rowspan=3|{{val|85|(5)|u=ms}} | β⁻n ({{val|87|(3)|u=%}}) | {{SimpleNuclide|Oxygen|20}} | rowspan=3|(1/2−) | rowspan=3| | rowspan=3| |- | β⁻ ({{val|13|(3)|u=%}}) | {{SimpleNuclide|Oxygen|21}} |- | β⁻2n ? | {{SimpleNuclide|Oxygen|19}} ? |-id=Nitrogen-22 | rowspan=3|{{SimpleNuclide|Nitrogen|22}} | rowspan=3 style="text-align:right" | 7 | rowspan=3 style="text-align:right" | 15 | rowspan=3|{{val|22.03410|(22)}} | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/22.pdf 1979] | rowspan=3|{{val|23|(3)|u=ms}} | β⁻ ({{val|54.0|(4.2)|u=%}}) | {{SimpleNuclide|Oxygen|22}} | rowspan=3|0−# | rowspan=3| | rowspan=3| |- | β⁻n ({{val|34|(3)|u=%}}) | {{SimpleNuclide|Oxygen|21}} |- | β⁻2n ({{val|12|(3)|u=%}}) | {{SimpleNuclide|Oxygen|20}} |-id=Nitrogen-23 | rowspan=4|{{SimpleNuclide|Nitrogen|23}}<ref group="n">Heaviest particle-bound isotope of nitrogen, see Nuclear drip line</ref> | rowspan=4 style="text-align:right" | 7 | rowspan=4 style="text-align:right" | 16 | rowspan=4|{{val|23.03942|(45)}} | rowspan=4 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/23.pdf 1985] | rowspan=4|{{val|13.9|(1.4)|u=ms}} | β⁻ (> {{val|46.6|(7.2)|u=%}}) | {{SimpleNuclide|Oxygen|23}} | rowspan=4|1/2−# | rowspan=4| | rowspan=4| |- | β⁻n ({{val|42|(6)|u=%}}) | {{SimpleNuclide|Oxygen|22}} |- | β⁻2n ({{val|8|(4)|u=%}}) | {{SimpleNuclide|Oxygen|21}} |- | β⁻3n (< {{val|3.4|u=%}}) | {{SimpleNuclide|Oxygen|20}} |- | {{SimpleNuclide|Nitrogen|24}} | style="text-align:right" | 7 | style="text-align:right" | 17 | {{val|24.05039|(43)}}# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/24.pdf (2018)] | < {{val|52|u=ns}} | n ? | {{SimpleNuclide|Nitrogen|23}} ? | | | |-id=Nitrogen-25 | rowspan=2|{{SimpleNuclide|Nitrogen|25}} | rowspan=2 style="text-align:right" | 7 | rowspan=2 style="text-align:right" | 18 | rowspan=2|{{val|25.06010|(54)}}# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/7/25.pdf (2018)] | rowspan=2|< {{val|260|u=ns}} | n ? | {{SimpleNuclide|Nitrogen|24}} ? | rowspan=2|1/2−# | rowspan=2| | rowspan=2| |- | 2n ? | {{SimpleNuclide|Nitrogen|23}} ? |- {{Isotopes table/footer}}

==Nitrogen-13== Nitrogen-13 (¹³N) has a half-life of a little under ten minutes. It is produced in the atmosphere when gamma rays (for example from lightning) knock neutrons out of nitrogen-14.<ref>{{cite journal |url=https://www.nature.com/news/lightning-makes-new-isotopes-1.23033 |title=Lightning makes new isotopes |last=Castelvecchi|first=Davide |date=November 22, 2017 |journal=Nature |doi=10.1038/nature.2017.23033 |access-date=November 29, 2017 |quote=|url-access=subscription }}</ref>

¹³N decays to ¹³C, emitting a positron. The positron quickly annihilates with an electron, producing two gamma rays of about {{val|511|u=keV}}. After a lightning bolt, this gamma radiation dies down with a half-life of 10&nbsp;minutes, but these low-energy gamma rays go on average only about 90 metres through the air, so they may only be detected for a minute or so as the "cloud" of ¹³N and ¹⁵O floats by, carried by the wind.<ref>{{cite journal|last1=Teruaki Enoto|display-authors=etal|title=Photonuclear reactions triggered by lightning discharge|journal=Nature|volume=551|issue=7681|pages=481–484|date=Nov 23, 2017|doi=10.1038/nature24630|pmid=29168803|bibcode=2017Natur.551..481E|arxiv=1711.08044|s2cid=4388159}}</ref>

Nitrogen-13 plays a significant role in the CNO cycle, which is the dominant source of energy in main sequence stars more massive than 1.5 times the mass of the Sun.<ref>{{cite book|author=Phillips, A.C. |title=The Physics of Stars |publisher=John Wiley & Sons |year=1994|isbn=0-471-94057-7}} </ref>

Nitrogen-13 is used in positron emission tomography in the form of ¹³N-labelled ammonia, for example for myocardial perfusion imaging. It can be produced with a medical cyclotron, using a target of pure water with a trace amount of ethanol. The reactants are oxygen-16 (present as H₂O) and a proton, and the products are nitrogen-13 and an alpha particle (helium-4): :{{chem2|^{1}H + ^{16}O -> ^{13}N + ^{4}He}}

In this endothermic reaction, the proton must be accelerated to have a total energy greater than 5.66&nbsp;MeV.<ref name=13Nplos>{{cite journal |last1=Islam |first1=M. R. |last2=Beni |first2=M. S. |last3=Ng |first3=C |display-authors=et al. |date=2022 |title=Proton range monitoring using ¹³N peak for proton therapy applications |journal=PLOS ONE |volume=17 |issue=2 |pages=e0263521-1–e0263521-18 |doi=10.1371/journal.pone.0263521|pmid=35167589 |doi-access=free |pmc=8846528 |bibcode=2022PLoSO..1763521I }}</ref> The presence of ethanol allows the formation of ammonia as nitrogen-13 is produced. Other routes of producing ¹³N-labelled ammonia exist, some of which facilitate co-generation of other light radionuclides for diagnostic imaging.<ref>{{cite web | last1=Biricova | first1=Veronika | last2=Kuruc | first2= Jozef | title=Synthesis of the radiopharmaceuticals for positron emission tomography | url=https://www.osti.gov/etdeweb/servlets/purl/20895812 | date=2007 | publisher=U.S. Department of Energy, Office of Scientific and Technical Information | access-date=4 August 2022}}</ref><ref>{{cite journal | journal=EJNMMI Radiopharm Chem. | volume=5 | issue=11 | doi=10.1186/s41181-020-00097-7 | date=13 May 2020 | pmid=32405797 | last1=Yokell | first1=Daniel L. | last2=Rice |first2=Peter A. | last3=Neelamegam | first3=Ramesh | last4=El Fakhri | first4=Georges | title=Development, validation and regulatory acceptance of improved purification and simplified quality control of [¹³N] Ammonia | page=11 | doi-access=free | pmc=7221112 }}</ref>

==Nitrogen-14== Nitrogen-14 makes up the clear majority of natural nitrogen, about 99.62%, and is responsible for the Earth's stable atmosphere.

Nitrogen-14 is one of the very few stable nuclides with both an odd number of protons and of neutrons (seven each) and is the only one to make up a majority of its element. Unpaired protons or neutrons contribute a half-integer nuclear spin, which in this case is a spin 1/2 orbital, giving the nucleus a total magnetic spin of one (as the spins prefer to align).

The original source of nitrogen-14 and nitrogen-15 in the Universe is believed to be stellar nucleosynthesis, where they are produced as part of the CNO cycle.

Nitrogen-14 is the source of naturally occurring, radioactive, carbon-14. Some kinds of cosmic radiation cause a nuclear reaction with nitrogen-14 in the upper atmosphere of the Earth, creating carbon-14, which decays back to nitrogen-14 with a half-life of {{val|5700|u=years}}.

==Nitrogen-15== Nitrogen-15 is a rare stable isotope of nitrogen, comprising about 0.38%. Nitrogen-15 presents one of the lowest thermal neutron capture cross sections of all isotopes.<ref>{{cite web |url=http://www.nndc.bnl.gov/sigma/index.jsp?as=15&lib=endfb7.1&nsub=10 |title=Evaluated Nuclear Data File (ENDF) Retrieval & Plotting |publisher=National Nuclear Data Center}}</ref>

Nitrogen-15 is frequently used in NMR (Nitrogen-15 NMR spectroscopy). Unlike the more abundant nitrogen-14, which has an integer nuclear spin and thus a quadrupole moment, ¹⁵N has a fractional nuclear spin of one-half, which offers advantages for NMR such as narrower line width. As most nitrogen NMR studies look at a single nitrogen atom in an organic molecule, isotopic labeling is feasible.

Nitrogen-15 tracing is a technique used to study the nitrogen cycle.

==Nitrogen-16== The radioisotope ¹⁶N is the dominant radioactivity source in the coolant water of nuclear reactors cooled by water during normal operation. It is produced from ¹⁶O (in water) via an (n,p) reaction, in which the ¹⁶O atom captures a neutron and expels a proton. It has a short half-life of 7.13 seconds, but its decay back to ¹⁶O produces high-energy gamma radiation (6.13 MeV principal line<ref>{{NNDC}}</ref>).<ref name="Neeb-1997">{{Cite book|last=Neeb|first=Karl Heinz|title=The Radiochemistry of Nuclear Power Plants with Light Water Reactors|publisher=Walter de Gruyter|location=Berlin-New York|date=1997|isbn=978-3-11-013242-7|url=https://books.google.com/books?id=SJOE00whg44C&pg=PA227|page=227|access-date=2015-12-20|archive-date=2016-02-05|archive-url=https://web.archive.org/web/20160205191759/https://books.google.com/books?id=SJOE00whg44C&pg=PA227|url-status=live}}</ref> Because of this, access to the primary coolant piping in a pressurised water reactor must be restricted during reactor power operation.<ref name="Neeb-1997" /> It is a sensitive and immediate indicator of leaks from the primary coolant system to the secondary steam cycle and is the primary means of detection for such leaks.<ref name="Neeb-1997"/>

==Isotopic signatures== {{main|Isotopic signature#Nitrogen isotopes}}

==See also== * Isotopes of oxygen * Isotopes of carbon * Isotopes of beryllium * Isotopes of helium

== References == {{reflist}}

{{Navbox element isotopes}}

Category:Isotopes of nitrogen Category:Nitrogen Nitrogen