Isotopes of nitrogen

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Isotopes of nitrogen  (7N)
Main isotopes Decay
abun­dance half-life (t1/2) mode pro­duct
13N trace 9.965 min β+ 13C
14N99.6% stable
15N0.4%stable
16N synth 7.13 s β− 16O
β−α<0.01% 12C
Standard atomic weight Ar°(N)

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, along with three nuclear isomers. All of these radioisotopes are short-lived, the longest-lived being nitrogen-13 with a half-life of 9.965(4) min. 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 numbers below 14 decay to isotopes of carbon, while most of the isotopes with masses above 15 decay to isotopes of oxygen. The shortest-lived known isotope is nitrogen-10, with a half-life of 143(36)  yoctoseconds , though the half-life of nitrogen-9 has not been measured exactly.

Contents

List of isotopes

Nuclide
[n 1] 		Z N Isotopic mass (Da) [3]
[n 2] [n 3] 		Half-life [4]

[resonance width]		 Decay
mode [4]
[n 4] 		Daughter
isotope
[n 5] 		Spin and
parity [4]
[n 6] [n 7] 		Natural abundance (mole fraction)
Excitation energyNormal proportion [4] Range of variation
9
N
 [5] 		72<1 as [5] 5p [n 8] 4
He
10
N
7310.04165(43)143(36) ys p  ? [n 9] 9
C
 ?		1−, 2−
11
N
7411.026158(5)585(7) ys
[780.0(9.3) keV]		p10
C
1/2+
11m
N
740(60) keV690(80) ysp1/2−
12
N
7512.0186132(11)11.000(16) ms β+ (98.07(4)%)12
C
1+
β+α (1.93(4)%)8
Be
 [n 10]
13
N
 [n 11] 		7613.00573861(29)9.965(4) minβ+13
C
1/2−
14
N
 [n 12] 		7714.003074004251(241)Stable1+[0.99578, 0.99663] [6]
14m
N
2312.590(10) keV IT 14
N
0+
15
N
7815.000108898266(625)Stable1/2−[0.00337, 0.00422] [6]
16
N
7916.0061019(25)7.13(2) sβ− (99.99846(5)%)16
O
2−
β−α (0.00154(5)%)12
C
16m
N
120.42(12) keV5.25(6) μsIT (99.999611(25)%)16
N
0−
β− (0.000389(25)%)16
O
17N71017.008449(16)4.173(4) sβ−n (95.1(7)%)16
O
1/2−
β− (4.9(7)%)17
O
β−α (0.0025(4)%)13
C
18
N
71118.014078(20)619.2(1.9) msβ− (80.8(1.6)%)18
O
1−
β−α (12.2(6)%)14
C
β−n (7.0(1.5)%)17
O
β−2n ? [n 9] 16
O
 ?
19
N
71219.017022(18)336(3) msβ− (58.2(9)%)19
O
1/2−
β−n (41.8(9)%)18
O
20
N
71320.023370(80)136(3) msβ− (57.1(1.4)%)20
O
(2−)
β−n (42.9(1.4)%)19
O
β−2n ? [n 9] 18
O
 ?
21
N
71421.02709(14)85(5) msβ−n (87(3)%)20
O
(1/2−)
β− (13(3)%)21
O
β−2n ? [n 9] 19
O
 ?
22
N
71522.03410(22)23(3) msβ− (54.0(4.2)%)22
O
0−#
β−n (34(3)%)21
O
β−2n (12(3)%)20
O
23
N
 [n 13] 		71623.03942(45)13.9(1.4) msβ− (> 46.6(7.2)%)23
O
1/2−#
β−n (42(6)%)22
O
β−2n (8(4)%)21
O
β−3n (< 3.4%)20
O
This table header & footer:
  1. ↑ mN – Excited nuclear isomer.
  2. ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ↑ Modes of decay:
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  5. ↑ Bold symbol as daughter – Daughter product is stable.
  6. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  7. ↑ # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  8. ↑ Decays by proton emission to 8
    C
    , which immediately emits two protons to form 6
    Be
    , which in turn emits two protons to form stable 4
    He
     [5]
  9. 1 2 3 4 Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.
  10. ↑ Immediately decays into two alpha particles for a net reaction of 12N → 3 4He + e+.
  11. ↑ Used in positron emission tomography
  12. ↑ One of the few stable odd-odd nuclei
  13. ↑ Heaviest particle-bound isotope of nitrogen, see Nuclear drip line

Nitrogen-13

Nitrogen-13 and oxygen-15 are produced in the atmosphere when gamma rays (for example from lightning) 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 9.965(4) min to carbon-13, emitting a positron. The positron quickly annihilates with an electron, producing two gamma rays of about 511 keV. 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. [7]

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 of plus or minus spin 1/2, giving the nucleus a total magnetic spin of one.

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 5700(30) years.

Nitrogen-15

Nitrogen-15 is a rare stable isotope of nitrogen. Two sources of nitrogen-15 are the positron emission of oxygen-15 [8] and the beta decay of carbon-15. Nitrogen-15 presents one of the lowest thermal neutron capture cross sections of all isotopes. [9]

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.

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

Nitrogen-16

The radioisotope 16N is the dominant radionuclide in the coolant of pressurised water reactors or boiling water reactors 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, [4] but its decay back to 16O produces high-energy gamma radiation (5 to 7 MeV). [4] [10] Because of this, access to the primary coolant piping in a pressurised water reactor must be restricted during reactor power operation. [10] 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. [10]

Isotopic signatures

Related Research Articles

<span class="mw-page-title-main">Atom</span> Smallest unit of a chemical element

Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element.

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 ways: emitted from the nucleus as gamma radiation; transferred to one of its electrons to release it as a conversion electron; or used to create and emit a new particle (alpha particle or beta particle) from the nucleus. During those processes, the radionuclide is said to undergo radioactive decay. These emissions are considered ionizing radiation because they are energetic enough to liberate an electron from another atom. The radioactive decay can produce a stable nuclide or will sometimes produce a new unstable radionuclide which may undergo further decay. Radioactive decay is a random process at the level of single atoms: it is impossible to predict when one particular atom will decay. However, for a collection of atoms of a single nuclide the decay rate, and thus the half-life (t1/2) for that collection, can be calculated from their measured decay constants. The range of the half-lives of radioactive atoms has no known limits and spans a time range of over 55 orders of magnitude.

<span class="mw-page-title-main">Positron emission</span> Type of radioactive decay

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 emission is mediated by the weak force. The positron is a type of beta particle (β+), the other beta particle being the electron (β−) emitted from the β− decay of a nucleus.

A radioactive tracer, radiotracer, or radioactive label is a synthetic derivative of a natural compound in which one or more atoms have been replaced by a radionuclide. By virtue of its radioactive decay, it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling or radiotracing is thus the radioactive form of isotopic labeling. In biological contexts, experiments that use radioisotope tracers are sometimes called radioisotope feeding experiments.

<span class="mw-page-title-main">Neutron activation</span> Induction of radioactivity by neutron radiation

Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emitting gamma rays, or particles such as beta particles, alpha particles, fission products, and neutrons. Thus, the process of neutron capture, even after any intermediate decay, often results in the formation of an unstable activation product. Such radioactive nuclei can exhibit half-lives ranging from small fractions of a second to many years.

<span class="mw-page-title-main">Isotopes of hydrogen</span>

Hydrogen (1H) has three naturally occurring isotopes: 1H, 2H, and 3H. 1H and 2H are stable, while 3H has a half-life of 12.32(2) years. Heavier isotopes also exist; all are synthetic and have a half-life of less than 1 zeptosecond (10−21 s). Of these, 5H is the least stable, while 7H is the most.

Fluorine (9F) has 19 known isotopes ranging from 13
F
 to 31
F
 and two isomers. Only fluorine-19 is stable and naturally occurring in more than trace quantities; therefore, fluorine is a monoisotopic and mononuclidic element.

Naturally occurring lithium (3Li) is composed of two stable isotopes, lithium-6 (6Li) and lithium-7 (7Li), with the latter being far more abundant on Earth. Both of the natural isotopes have an unexpectedly low nuclear binding energy per nucleon when compared with the adjacent lighter and heavier elements, helium and beryllium. The longest-lived radioisotope of lithium is 8Li, which has a half-life of just 838.7(3) milliseconds. 9Li has a half-life of 178.2(4) ms, and 11Li has a half-life of 8.75(6) ms. All of the remaining isotopes of lithium have half-lives that are shorter than 10 nanoseconds. The shortest-lived known isotope of lithium is 4Li, which decays by proton emission with a half-life of about 91(9) yoctoseconds, although the half-life of 3Li is yet to be determined, and is likely to be much shorter, like 2He which undergoes proton emission within 10−9 s.

Lead (82Pb) has four observationally stable isotopes: 204Pb, 206Pb, 207Pb, 208Pb. Lead-204 is entirely a primordial nuclide and is not a radiogenic nuclide. The three isotopes lead-206, lead-207, and lead-208 represent the ends of three decay chains: the uranium series, the actinium series, and the thorium series, respectively; a fourth decay chain, the neptunium series, terminates with the thallium isotope 205Tl. The three series terminating in lead represent the decay chain products of long-lived primordial 238U, 235U, and 232Th. Each isotope also occurs, to some extent, as primordial isotopes that were made in supernovae, rather than radiogenically as daughter products. The fixed ratio of lead-204 to the primordial amounts of the other lead isotopes may be used as the baseline to estimate the extra amounts of radiogenic lead present in rocks as a result of decay from uranium and thorium.

<span class="mw-page-title-main">Isotopes of iodine</span>

There are 40 known isotopes of iodine (53I) from 108I to 147I; all undergo radioactive decay except 127I, which is stable. Iodine is thus a monoisotopic element.

Tin (50Sn) is the element with the greatest number of stable isotopes. This is probably related to the fact that 50 is a "magic number" of protons. In addition, twenty-nine unstable tin isotopes are known, including tin-100 (100Sn) and tin-132 (132Sn), which are both "doubly magic". The longest-lived tin radioisotope is tin-126 (126Sn), with a half-life of 230,000 years. The other 28 radioisotopes have half-lives of less than a year.

Technetium (43Tc) is one of the two elements with Z < 83 that have no stable isotopes; the other such element is promethium. It is primarily artificial, with only trace quantities existing in nature produced by spontaneous fission or neutron capture by molybdenum. The first isotopes to be synthesized were 97Tc and 99Tc in 1936, the first artificial element to be produced. The most stable radioisotopes are 97Tc, 98Tc, and 99Tc.

Naturally occurring zirconium (40Zr) is composed of four stable isotopes (of which one may in the future be found radioactive), and one very long-lived radioisotope (96Zr), a primordial nuclide that decays via double beta decay with an observed half-life of 2.0×1019 years; it can also undergo single beta decay, which is not yet observed, but the theoretically predicted value of t1/2 is 2.4×1020 years. The second most stable radioisotope is 93Zr, which has a half-life of 1.53 million years. Thirty other radioisotopes have been observed. All have half-lives less than a day except for 95Zr (64.02 days), 88Zr (83.4 days), and 89Zr (78.41 hours). The primary decay mode is electron capture for isotopes lighter than 92Zr, and the primary mode for heavier isotopes is beta decay.

Potassium has 25 known isotopes from 34
K to 57
K as well as 31
K, as well as an unconfirmed report of 59
K. Three of those isotopes occur naturally: the two stable forms 39
K (93.3%) and 41
K (6.7%), and a very long-lived radioisotope 40
K (0.012%)

There are 20 isotopes of sodium (11Na), ranging from 17
Na to 39
Na, and two isomers. 23
Na is the only stable isotope. It is considered a monoisotopic element and it has a standard atomic weight of 22.98976928(2). Sodium has two radioactive cosmogenic isotopes. With the exception of those two isotopes, all other isotopes have half-lives under a minute, most under a second. The shortest-lived is the unbound 18
Na, with a half-life of 1.3(4)×10−21 seconds.

There are three known stable isotopes of oxygen (8O): 16
O
, 17
O
, and 18
O
.

Carbon (6C) has 14 known isotopes, from 8
C
 to 20
C
 as well as 22
C
, of which 12
C
 and 13
C
 are stable. The longest-lived radioisotope is 14
C
, with a half-life of 5.70(3)×103 years. This is also the only carbon radioisotope found in nature, as trace quantities are formed cosmogenically by the reaction 14
N
 +
n
 → 14
C
 + 1
H
. The most stable artificial radioisotope is 11
C
, which has a half-life of 20.3402(53) min. All other radioisotopes have half-lives under 20 seconds, most less than 200 milliseconds. The least stable isotope is 8
C
, with a half-life of 3.5(1.4)×10−21 s. Light isotopes tend to decay into isotopes of boron and heavy ones tend to decay into isotopes of nitrogen.

Oxygen-17 (17O) is a low-abundance, natural, stable isotope of oxygen.

A table or chart of nuclides is a two-dimensional graph of isotopes of the elements, in which one axis represents the number of neutrons and the other represents the number of protons in the atomic nucleus. Each point plotted on the graph thus represents a nuclide of a known or hypothetical chemical element. This system of ordering nuclides can offer a greater insight into the characteristics of isotopes than the better-known periodic table, which shows only elements and not their isotopes. The chart of the nuclides is also known as the Segrè chart, after the Italian physicist Emilio Segrè.

<span class="mw-page-title-main">Isotope</span> Different atoms of the same element

Isotopes are distinct nuclear species of the same chemical element. They have the same atomic number and position in the periodic table, but different nucleon numbers due to different numbers of neutrons in their nuclei. While all isotopes of a given element have similar chemical properties, they have different atomic masses and physical properties.

References

  1. ↑ "Standard Atomic Weights: Nitrogen". CIAAW. 2009.
  2. ↑ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN   1365-3075.
  3. ↑ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
  4. 1 2 3 4 5 6 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  5. 1 2 3 Cho, Adrian (25 September 2023). "Fleeting form of nitrogen stretches nuclear theory to its limits". science.org . Retrieved 27 September 2023.
  6. 1 2 "Atomic Weight of Nitrogen | Commission on Isotopic Abundances and Atomic Weights". ciaaw.org. Retrieved 2022-02-26.
  7. ↑ Teruaki Enoto; et al. (Nov 23, 2017). "Photonuclear reactions triggered by lightning discharge". Nature. 551 (7681): 481–484. arXiv: 1711.08044 . Bibcode:2017Natur.551..481E. doi:10.1038/nature24630. PMID   29168803. S2CID   4388159.
  8. ↑ CRC Handbook of Chemistry and Physics (64th ed.). 1983–1984. p. B-234.
  9. ↑ "Evaluated Nuclear Data File (ENDF) Retrieval & Plotting". National Nuclear Data Center.
  10. 1 2 3 Neeb, Karl Heinz (1997). The Radiochemistry of Nuclear Power Plants with Light Water Reactors. Berlin-New York: Walter de Gruyter. p. 227. ISBN   978-3-11-013242-7. Archived from the original on 2016-02-05. Retrieved 2015-12-20.
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