Natural

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

(₇N) consists of two stable

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

s: the vast majority (99.6%) of naturally occurring nitrogen is

nitrogen-14 Natural nitrogen (7N) consists of two stable isotopes: the vast majority (99.6%) of naturally occurring nitrogen is nitrogen-14, with the remainder being nitrogen-15. Thirteen radioisotopes are also known, with atomic masses ranging from 9 to 23, ...

, with the remainder being

nitrogen-15 Natural nitrogen (7N) consists of two stable isotopes: the vast majority (99.6%) of naturally occurring nitrogen is nitrogen-14, with the remainder being nitrogen-15. Thirteen radioisotopes are also known, with atomic masses ranging from 9 to 23, ...

. Thirteen

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

s are also known, with

atomic mass Atomic mass ( or ) is the mass of a single atom. The atomic mass mostly comes from the combined mass of the protons and neutrons in the nucleus, with minor contributions from the electrons and nuclear binding energy. The atomic mass of atoms, ...

es ranging from 9 to 23, along with three

nuclear isomer A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state levels (higher energy levels). "Metastable" describes nuclei whose excited states have Half-life, half-lives of ...

s. All of these radioisotopes are short-lived, the longest-lived being nitrogen-13 with a half-life of . All of the others have half-lives shorter than ten seconds, with most of these being below 500 milliseconds. Most of the isotopes with

atomic mass number The mass number (symbol ''A'', from the German word: ''Atomgewicht'', "atomic weight"), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It is approx ...

s below 14 decay to

isotopes of carbon Carbon (6C) has 14 known isotopes, from to as well as , of which only and are stable. The longest-lived radioisotope is , with a half-life of years. This is also the only carbon radioisotope found in nature, as trace quantities are formed ...

, while most of the isotopes with masses above 15 decay to

isotopes of oxygen There are three known stable isotopes of oxygen (8O): , , and . Radioactive isotopes ranging from to have also been characterized, all short-lived. The longest-lived radioisotope is with a half-life of , while the shortest-lived isotope i ...

. The shortest-lived known isotope is nitrogen-10, with a half-life of , though the half-life of nitrogen-9 has not been measured exactly.

List of isotopes

, -id=Nitrogen-9 , , style="text-align:right" , 7 , style="text-align:right" , 2 , , <1 as , 5p , , , , , -id=Nitrogen-10 , , style="text-align:right" , 7 , style="text-align:right" , 3 , , , p ?Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide. , ? , 1−, 2− , , , -id=Nitrogen-11 , , style="text-align:right" , 7 , style="text-align:right" , 4 , ,
[] , p , , 1/2+ , , , -id=Nitrogen-11m , style="text-indent:1em" , , colspan="3" style="text-indent:2em" , , , p , , 1/2− , , , -id=Nitrogen-12 , rowspan=2, , rowspan=2 style="text-align:right" , 7 , rowspan=2 style="text-align:right" , 5 , rowspan=2, , rowspan=2, , β⁺ () , , rowspan=2, 1+ , rowspan=2, , rowspan=2, , - , β⁺α () , Immediately decays into two alpha particles for a net reaction of ¹²N → 3 ⁴He + e⁺. , - , Used in

positron emission tomography Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, r ...

, style="text-align:right" , 7 , style="text-align:right" , 6 , , , β⁺ , , 1/2− , , , - , One of the few stable odd-odd nuclei , style="text-align:right" , 7 , style="text-align:right" , 7 , , colspan=3 align=center, Stable , 1+ , ref name="Atomic Weight of Nitrogen"> , , -id=Nitrogen-14m , style="text-indent:1em" , , colspan="3" style="text-indent:2em" , , , IT , , 0+ , , , - , , style="text-align:right" , 7 , style="text-align:right" , 8 , , colspan=3 align=center, Stable , 1/2− , ref name="Atomic Weight of Nitrogen" /> , , - , rowspan=2, , rowspan=2 style="text-align:right" , 7 , rowspan=2 style="text-align:right" , 9 , rowspan=2, , rowspan=2, , β⁻ () , , rowspan=2, 2− , rowspan=2, , rowspan=2, , - , β⁻α () , , -id=Nitrogen-16m , rowspan=2 style="text-indent:1em" , , rowspan=2 colspan="3" style="text-indent:2em" , , rowspan=2, , IT () , , rowspan=2, 0− , rowspan=2, , rowspan=2, , - , β⁻ () , , -id=Nitrogen-17 , rowspan=3, ¹⁷N , rowspan=3 style="text-align:right" , 7 , rowspan=3 style="text-align:right" , 10 , rowspan=3, , rowspan=3, , β⁻n () , , rowspan=3, 1/2− , rowspan=3, , rowspan=3, , - , β⁻ () , , - , β⁻α () , , -id=Nitrogen-18 , rowspan=4, , rowspan=4 style="text-align:right" , 7 , rowspan=4 style="text-align:right" , 11 , rowspan=4, , rowspan=4, , β⁻ () , , rowspan=4, 1− , rowspan=4, , rowspan=4, , - , β⁻α () , , - , β⁻n () , , - , β⁻2n ? , ? , -id=Nitrogen-19 , rowspan=2, , rowspan=2 style="text-align:right" , 7 , rowspan=2 style="text-align:right" , 12 , rowspan=2, , rowspan=2, , β⁻ () , , rowspan=2, 1/2− , rowspan=2, , rowspan=2, , - , β⁻n () , , -id=Nitrogen-20 , rowspan=3, , rowspan=3 style="text-align:right" , 7 , rowspan=3 style="text-align:right" , 13 , rowspan=3, , rowspan=3, , β⁻ () , , rowspan=3, (2−) , rowspan=3, , rowspan=3, , - , β⁻n () , , - , β⁻2n ? , ? , -id=Nitrogen-21 , rowspan=3, , rowspan=3 style="text-align:right" , 7 , rowspan=3 style="text-align:right" , 14 , rowspan=3, , rowspan=3, , β⁻n () , , rowspan=3, (1/2−) , rowspan=3, , rowspan=3, , - , β⁻ () , , - , β⁻2n ? , ? , -id=Nitrogen-22 , rowspan=3, , rowspan=3 style="text-align:right" , 7 , rowspan=3 style="text-align:right" , 15 , rowspan=3, , rowspan=3, , β⁻ () , , rowspan=3, 0−# , rowspan=3, , rowspan=3, , - , β⁻n () , , - , β⁻2n () , , -id=Nitrogen-23 , rowspan=4, Heaviest particle-bound isotope of nitrogen, see

Nuclear drip line The nuclear drip line is the boundary beyond which atomic nuclei are unbound with respect to the emission of a proton or neutron. An arbitrary combination of protons and neutrons does not necessarily yield a stable atomic nucleus, nucleus. One ...

, rowspan=4 style="text-align:right" , 7 , rowspan=4 style="text-align:right" , 16 , rowspan=4, , rowspan=4, , β⁻ (> ) , , rowspan=4, 1/2−# , rowspan=4, , rowspan=4, , - , β⁻n () , , - , β⁻2n () , , - , β⁻3n (< ) ,

Nitrogen-13

Nitrogen-13 and oxygen-15 are produced in the atmosphere when

gamma rays A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

(for example from

lightning Lightning is a natural phenomenon consisting of electrostatic discharges occurring through the atmosphere between two electrically charged regions. One or both regions are within the atmosphere, with the second region sometimes occurring on ...

) knock neutrons out of nitrogen-14 and oxygen-16: :¹⁴N + γ → ¹³N + n :¹⁶O + γ → ¹⁵O + n The nitrogen-13 produced as a result decays with a half-life of to carbon-13, emitting a

positron The positron or antielectron is the particle with an electric charge of +1''elementary charge, e'', a Spin (physics), spin of 1/2 (the same as the electron), and the same Electron rest mass, mass as an electron. It is the antiparticle (antimatt ...

. The positron quickly annihilates with an electron, producing two gamma rays of about . After a lightning bolt, this gamma radiation dies down with a half-life of ten minutes, but these low-energy gamma rays go only about 90 metres through the air on average, so they may only be detected for a minute or so as the "cloud" of ¹³N and ¹⁵O floats by, carried by the wind.

Nitrogen-14

Nitrogen-14 makes up about 99.636% of natural nitrogen. 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. Each proton or neutron contributes a

nuclear spin Nuclear may refer to: Physics Relating to the nucleus of the atom: * Nuclear engineering * Nuclear physics * Nuclear power * Nuclear reactor * Nuclear weapon * Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics * Nuclear space * ...

of plus or minus

spin 1/2 In quantum mechanics, spin is an intrinsic property of all elementary particles. All known fermions, the particles that constitute ordinary matter, have a spin of . The spin number describes how many symmetrical facets a particle has in one f ...

, giving the nucleus a total magnetic

spin Spin or spinning most often refers to: * Spin (physics) or particle spin, a fundamental property of elementary particles * Spin quantum number, a number which defines the value of a particle's spin * Spinning (textiles), the creation of yarn or thr ...

of one. The original source of nitrogen-14 and nitrogen-15 in the

Universe The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...

is believed to be

stellar nucleosynthesis In astrophysics, stellar nucleosynthesis is the creation of chemical elements by nuclear fusion reactions within stars. Stellar nucleosynthesis has occurred since the original creation of hydrogen, helium and lithium during the Big Bang. As a ...

, where they are produced as part of the

CNO cycle In astrophysics, the carbon–nitrogen–oxygen (CNO) cycle, sometimes called Bethe–Weizsäcker cycle, after Hans Albrecht Bethe and Carl Friedrich von Weizsäcker, is one of the two known sets of fusion reactions by which stars convert h ...

. Nitrogen-14 is the source of naturally-occurring, radioactive,

carbon-14 Carbon-14, C-14, C or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic matter is the basis of the radiocarbon dating method pioneered by Willard Libby and coll ...

. Some kinds of

cosmic radiation Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Sol ...

cause a

nuclear reaction In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two atomic nucleus, nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a t ...

with nitrogen-14 in the upper atmosphere of the Earth, creating carbon-14, which decays back to nitrogen-14 with a

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''Half Life: ...

of .

Nitrogen-15

Nitrogen-15 is a rare stable

. Two sources of nitrogen-15 are the

positron emission Positron emission, beta plus decay, or β+ decay is a subtype of radioactive decay called beta decay, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino (). Positron emi ...

oxygen-15 There are three known stable isotopes of oxygen (8O): , , and . Radioactive isotopes ranging from to have also been characterized, all short-lived. The longest-lived radioisotope is with a half-life of , while the shortest-lived isotope is ...

and the

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which an atomic nucleus emits a beta particle (fast energetic electron or positron), transforming into an isobar of that nuclide. For example, beta decay of a neutron ...

of carbon-15. Nitrogen-15 presents one of the lowest thermal neutron capture cross sections of all isotopes. Nitrogen-15 is frequently used in NMR ( Nitrogen-15 NMR spectroscopy). Unlike the more abundant nitrogen-14, which has an integer

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics * Nuclear space *Nuclear ...

and thus a quadrupole moment, ¹⁵N has a fractional

of one-half, which offers advantages for NMR such as narrower line width. Nitrogen-15 tracing is a technique used to study the

nitrogen cycle The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, atmospheric, terrestrial ecosystem, terrestrial, and marine ecosystems. The conversion of nitrogen can ...

Nitrogen-16

The radioisotope ¹⁶N is the dominant radionuclide in the coolant of reactors refrigerated by water or

boiling water reactor A boiling water reactor (BWR) is a type of nuclear reactor used for the generation of electrical power. It is the second most common type of electricity-generating nuclear reactor after the pressurized water reactor (PWR). BWR are thermal neutro ...

s 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 about 7.1 s, but its decay back to ¹⁶O produces high-energy

gamma radiation A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

(5 to 7 MeV). Because of this, access to the primary coolant piping in a pressurised water reactor must be restricted during reactor power operation. 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.

Isotopic signatures

References

{{Navbox element isotopes Nitrogen

Nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...