Natural

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

(₇N) consists of two stable

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...

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. Fourteen radioisotopes are also known, with atomic masses ranging from 10 to 25, ...

, 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. Fourteen radioisotopes are also known, with atomic masses ranging from 10 to 25, ...

. Fourteen

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

s are also known, with

atomic mass The atomic mass (''m''a or ''m'') is the mass of an atom. Although the SI unit of mass is the kilogram (symbol: kg), atomic mass is often expressed in the non-SI unit dalton (symbol: Da) – equivalently, unified atomic mass unit (u). 1&nb ...

es ranging from 10 to 25, along with one

nuclear isomer A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ...

, ^11mN. 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 below 7.15 seconds, with most of these being below 620 milliseconds. Most of the isotopes with

atomic mass number The mass number (symbol ''A'', from the German word ''Atomgewicht'' tomic 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 approxim ...

s below 14 decay to

isotopes of carbon Carbon (6C) has 15 known isotopes, from to , of which and are stable. The longest-lived radioisotope is , with a half-life of years. This is also the only carbon radioisotope found in nature—trace quantities are formed cosmogenically by t ...

, 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 is ...

. The shortest-lived known isotope is nitrogen-10, with a half-life of .

List of isotopes

, - , , 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− , , , - , , style="text-align:right" , 7 , style="text-align:right" , 4 , ,
[] , p , , 1/2+ , , , - , style="text-indent:1em" , , colspan="3" style="text-indent:2em" , , , p , , 1/2− , , , - , 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 , 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"> , , - , 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 () , , - , 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⁻ () , , - , 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 () , , - , 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 ? , ? , - , 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 () , , - , 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 ? , ? , - , 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 ? , ? , - , 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 () , , - , rowspan=4, , 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 (< ) , , - , ?This isotope has not yet been observed; given data is inferred or estimated from periodic trends. , style="text-align:right" , 7 , style="text-align:right" , 17 , # , < , n ? , ? , , , , - , rowspan=3, ? , rowspan=3 style="text-align:right" , 7 , rowspan=3 style="text-align:right" , 18 , rowspan=3, # , rowspan=3, < , n ? , ? , rowspan=3, 1/2−# , rowspan=3, , rowspan=3, , - , 2n ? , ? , - , β⁻ ? , ?

Nitrogen-13

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

gamma rays A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

(for example from

lightning Lightning is a naturally occurring electrostatic discharge during which two electrically charged regions, both in the atmosphere or with one on the ground, temporarily neutralize themselves, causing the instantaneous release of an avera ...

) 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 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 is one of two stable ( non-radioactive)

isotopes Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...

of the

chemical element A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...

, which makes 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 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 fu ...

, giving the nucleus a total magnetic spin of one. Like all elements heavier than

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...

, the original source of nitrogen-14 and nitrogen-15 in the

Universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. ...

is believed to be stellar nucleosynthesis, where they are produced as part of the

carbon-nitrogen-oxygen cycle The CNO cycle (for carbon–nitrogen–oxygen; 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 hydrogen to helium ...

. Nitrogen-14 is the source of naturally-occurring, radioactive, carbon-14. Some kinds of cosmic radiation cause a

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

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 (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

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 ...

of oxygen-15 and the

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For ...

carbon-15 Carbon (6C) has 15 known isotopes, from to , of which and are stable. The longest-lived radioisotope is , with a half-life of years. This is also the only carbon radioisotope found in nature—trace quantities are formed cosmogenically by ...

. 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 spin and thus a

quadrupole moment A quadrupole or quadrapole is one of a sequence of configurations of things like electric charge or current, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure ref ...

, ¹⁵N has a fractional nuclear spin of one-half, which offers advantages for NMR such as narrower line width.

Nitrogen-15 tracing Nitrogen-15 (15N) tracing is a technique to study the nitrogen cycle using the heavier, stable nitrogen isotope 15 N. Despite the different weights, 15N is involved in the same chemical reactions as the more abundant 14N and is therefore used to t ...

is a technique used to study the nitrogen cycle.

Isotopic signatures

References

{{Navbox element isotopes Nitrogen

Nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...