Three stable isotopes of the chemical element oxygen occur in nature, of which the nuclide 16O is the most common with a proportion of over 99.7%:
| Atomic Mass ma | Quantity | Half-life | Spin | |
| Oxygen Isotopic mixture | 15,999 u | 100 % | ||
| Isotope 16O | 15,994914619(1) u | 99,757 % | stable | 0+ |
| Isotope 17O | 16,999131757(5) u | 0,03835(96) % | stable | 5/2+ |
| Isotope 18O | 17,999159613(5) u | 0,2045 % | stable | 0+ |
Due to fluctuations in the isotope ratio of natural oxygen, the atomic mass varies in the range from 15.99903 to 15.99977 u.
The number of unstable, radioactive oxygen isotopes known to date is currently 14; here the isotope 15O is the most long-lived with a half-life of just over 2 minutes.
The source for most of the oxygen-16 isotope lies in stellar processes. As the primary isotope, oxygen is formed at the end of the helium fusion chain. Oxygen-17, on the other hand, results as a by-product of the so-called hydrogen burning of stars (CNO cycle), oxygen-18 is produced by the reaction of 14N- with 4He nuclei.
In NMR spectroscopy, the 17O nucleus can be measured with a nuclear spin of 5/2; the other natural isotopes are NMR inactive.
Of the unstable oxygen nuclei, the 15O isotope is used in positron emission tomography.
| Isotope Nuclide | E | N | Atomic Mass [Nuclear Mass] {Mass Excess} | Spin I (h/2π) | Parent |
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 |
| Oxygen-11 | 118O | 3 | 11.05125(6) u [11.0468614 u] {47.73907 MeV} | (3/2-) | |
| Oxygen-12 | 128O | 4 | 12.034368(13) u [12.0299794 u] {32.01359 MeV} | 0+ | |
| Oxygen-13 | 138O | 5 | 13.024815(10) u [13.0204264 u] {23.11502 MeV} | (3/2-) | 15Ne 14F |
| Oxygen-14 | 148O | 6 | 14.008596706(27) u [14.0042081 u] {8.00778 MeV} | 0+ | |
| Oxygen-15 | 158O | 7 | 15.0030656(5) u [14.998677 u] {2.85559 MeV} | 1/2- | |
| Oxygen-16 | 168O | 8 | 15.994914619(1) u [15.990526 u] {-4.737 MeV} | 0+ | 16N |
| Oxygen-17 | 178O | 9 | 16.999131757(5) u [16.9947431 u] {-0.80876 MeV} | 5/2+ | 17N 17F |
| Oxygen-18 | 188O | 10 | 17.999159613(5) u [17.994771 u] {-0.78282 MeV} | 0+ | 18N 18F |
| Oxygen-19 | 198O | 11 | 19.0035780(28) u [18.9991894 u] {3.33289 MeV} | 5/2+ | 19N |
| Oxygen-20 | 208O | 12 | 20.0040754(9) u [19.9996868 u] {3.79621 MeV} | 0+ | 20N 21N |
| Oxygen-21 | 218O | 13 | 21.008655(13) u [21.0042664 u] {8.06208 MeV} | (5/2+) | 21N 22N 23N |
| Oxygen-22 | 228O | 14 | 22.00997(6) u [22.0055814 u] {9.287 MeV} | 0+ | 22N 23N |
| Oxygen-23 | 238O | 15 | 23.01570(13) u [23.0113114 u] {14.62446 MeV} | 1/2+ | |
| Oxygen-24 | 248O | 16 | 24.01986(18) u [24.0154714 u] {18.49947 MeV} | 0+ | |
| Oxygen-25 | 258O | 17 | 25.02934(18) u [25.0249514 u] {27.33003 MeV} | 3/2+ | |
| Oxygen-26 | 268O | 18 | 26.03721(18) u [26.0328214 u] {34.66089 MeV} | 0+ | |
| Oxygen-27 | 278O | 19 | 27.04796(54) u [27.0435714 u] {44.67445 MeV} | 3/2+ | |
| Oxygen-28 | 288O | 20 | 28.05591(75) u [28.0515214 u] {52.07983 MeV} | 0+ |
| Isotope | Radioactive Decay | Extern | |||
|---|---|---|---|---|---|
| Half-life | Decay Mode | Probability | Energy | ||
| 7 | 8 | 9 | 10 | 11 | 12 |
| O-11 | 198(12) ys | 2p 9C | 100 % | AL | |
| O-12 | 8.9(33) zs | 2p 10C | 14.675(12) MeV | AL | |
| O-13 | 8.58(5) ms | β+ → 13N β+, p → 12C | 89.1(2) % 10.9(2) % | 17.77(1) MeV 15.826(10) MeV | AL |
| O-14 | 70.621(11) s | EC,β+ → 14N | 100 % | 5.144364(25) MeV | AL |
| O-15 | 122.24(16) s | EC β+ → 15N | 100 % | 2.7542(5) MeV | AL |
| O-16 | stable | AL | |||
| O-17 | stable | AL | |||
| O-18 | stable | AL | |||
| O-19 | 26.470(6) s | β- → 19F | 100 % | 4.8203(26) MeV | AL |
| O-20 | 13.51(5) s | β- → 20F | 100 % | 3.8136(9) MeV | AL |
| O-21 | 3.42(10) s | β- → 21F β-, n → 20F | 100 % ? | 8.110(12) MeV | AL |
| O-22 | 2.25(9) s | β- → 22F β-, n → 21F | > 78 % < 22 % | 6.49(6) MeV 1.259(57) MeV | AL |
| O-23 | 0.097(8) s | β- → 23F β-, n → 22F | 93(2) % 7(2) % | 11.340(130) MeV 3.757(122) MeV | AL |
| O-24 | 0.0774(45) s | β- → 24F β-, n → 23F | 57(4) % 43(4) % | 10.96(19) MeV 7.144(168) MeV | AL |
| O-25 | 5.18 zs | n → 24O | 100 % | AL | |
| O-26 | 4.2(33) ps | 2n 24O | 100 % | AL | |
| O-27 | < 260 ns | 3n → 24O | |||
| O-28 | < 100 ns | 2n 26O | ? | ||
Notes (related to the columns):
1 - name of the nuclide, isotope.
2 - E: isotope symbol with mass number (superscript; number of nucleons) and Atomic number (subscript; number of protons).
3 - N: number of neutrons.
4 - relative atomic mass of the Oxygen isotope (isotopic mass including electrons) and the mass of the atomic nucleus in square brackets (nuclear mass, nuclide mass without electrons), each related to 12C = 12.00000 [2]. In addition, the mass excess is given in MeV.
5 - nuclear spin I, unit: h/2π.
6 - source nuclides: Possible, assumed or actual source nuclides (mother nuclides, parent nuclides). If applicable, the corresponding decay modes can be found in the data for the respective starting nuclide.
7 - isotope notation in short form.
8 - decay: half-live of the Oxygen isotope (a = years; ; d = days; h = hours; min = minutes; s = seconds).
9 - decay mode: type of decay into the respective daughter nuclides with n = neutron emission; p = proton emission; α = alpha decay; β- = beta minus decay with electron emission; EC = electron capture; β+ = positron emission; ε = β+ and/or EC; Iso = isomeric transition; CD = cluster decay; SF = spontaneous decay.
10 - decay probability in percent (%).
11 - decay energy; Particle energy related to decay type.
12 - other information and notes: AL = Adopted Levels (link to external data [1]).
Miscellaneous:
()- Numbers in brackets: uncertainty to represent the spread of the reported value.
~ - Theoretical values or systematic trends.
- unlisted-: Nuclides that have already been mentioned in the literature but for some reason can no longer be found in the current nuclide tables because their discovery e.g. has not confirmed.
| Nuclide quantity 1) spin | Nuclear magnetic moment μ/μN | Gyromagnetic ratio {Quadrupole moment} | Resonant frequency v0 bei 1 T | Relative sensitivity H0 = const. v0 = const. 3) |
|---|---|---|---|---|
| 17O 0,03835(96) % 5/2+ | -1,893543(10) | - 3,6279 {- 0,02558(22)} | 5,7742 | 0,02910 1,5822 |
1) Quantity Percentage of natural occurrence.
2) Gyromagnetic ratio: 107 rad T-1 s-1
Quadrupole moment: Q [barn] = [100 fm2]
3) Related to 1H = 1,000.
According to the Radiation Protection Ordinance (StrlSchV 2018, Germany), the following values (columns 1 to 7) apply to the handling of Oxygen radionuclides:
| Nuclide | Limit Value | HASS limit | SC | Daughter Nuclides | Half-life | |
|---|---|---|---|---|---|---|
| O-15 | 109 Bq | 100 Bq/g | 2.0 min | |||
(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)
Properties of the Oxygen nucleides
[1] - NuDat: National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards.
[2] - G. Audi et. al.: The NUBASE evaluation of nuclear and decay properties. Nuclear Physics, (2003), DOI 10.1016/j.nuclphysa.2003.11.001.
[3] - Live Chart of Nuclides. Nuclear structure and decay data.
Oxygen: NMR properties - 17O-NMR
[4] - N. J. Stone: Table of nuclear magnetic dipole and electric quadrupole moments. Atomic Data and Nuclear Data Tables, (2005), DOI 10.1016/j.adt.2005.04.001.
[5] - Pekka Pyykkö: Year-2008 nuclear quadrupole moments. Molecular Physics, (2008), DOI 10.1080/00268970802018367.
[6] - Pekka Pyykkö: Year-2017 nuclear quadrupole moments. Molecular Physics, (2018), DOI 10.1080/00268976.2018.1426131.
[7] - N. J. Stone: Table of recommended nuclear magnetic dipole moments. IAEA, (2019).
More sources:
[8] - Isotopic abundances, atomic weights and isotopic masses: see respective keyword.
Last update: 2022-12-12
Perma link: https://www.chemlin.org/chemical-elements/oxygen-isotopes.php
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