Notation: mass number as a left superscript (e.g., ¹⁵O).
Columns: Isotope | Z | A | Stable? | Half‑life | Decay mode(s) | Daughter | Radiation | Origin | Uses | Notes.
| Isotope | Z | A | Stable? | Half‑life | Decay mode(s) | Daughter | Radiation | Origin | Uses | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| ¹¹O | 8 | 11 | Unstable (unbound) | ~10⁻²¹ s (resonance) | 2p emission | ⁹C | protons | Synthetic (accelerators) | Research (mirror of ¹¹Li) | First observation as unbound 2p emitter (2019). (Physical Review Link) |
| ¹²O | 8 | 12 | Unstable (unbound) | ~10⁻²¹ s (resonance) | 2p emission | ¹⁰C | protons | Synthetic | Research (proton‑dripline) | Ground‑state 2p decay; broad unbound state. (actaphys.uj.edu.pl, Inspire-HEP) |
| ¹³O | 8 | 13 | Unstable | 8.58 ms | β⁺ (≈ 89%); β⁺p (≈ 11%) | ¹³N; ¹²C | β⁺; annihilation γ; delayed p (minor) | Synthetic; CNO‑cycle intermediate | Research; PET method development | Well‑measured t½ and branches. (ChemLin) |
| ¹⁴O | 8 | 14 | Unstable | 70.619 s | EC/β⁺ → ¹⁴N (100%) | ¹⁴N | β⁺; annihilation γ | Synthetic; stellar CNO | Superallowed 0⁺→0⁺ β‑decay benchmark | Modern precision half‑life measurements. (Atrium, arXiv) |
| ¹⁵O | 8 | 15 | Unstable | 122.24 s | β⁺ → ¹⁵N | ¹⁵N | β⁺; annihilation γ | Synthetic (cyclotron) | Medical PET (e.g., H₂¹⁵O for perfusion) | Clinical workhorse near site of production. (Journal of Nuclear Medicine, PubMed) |
| ¹⁶O | 8 | 16 | Stable | stable | — | — | — | Natural | Reference chemistry; oxides & materials | Most abundant O nuclide. |
| ¹⁷O | 8 | 17 | Stable | stable | — | — | — | Natural (trace) & Enriched | NMR/MRI tracer (H₂¹⁷O); metabolic O₂ studies | Only MR‑active stable O; used in ¹⁷O‑MRI. (NCBI, RSNA Publications) |
| ¹⁸O | 8 | 18 | Stable | stable | — | — | — | Natural (trace) & Enriched | Isotope hydrology & paleoclimate (δ¹⁸O); precursor to ¹⁸F via ¹⁸O(p,n)¹⁸F | Heavy‑water analogue; key PET feedstock. (USGS, PMC) |
| ¹⁹O | 8 | 19 | Unstable | 26.470 s | β⁻ (100%) | ¹⁹F | β⁻; γ (from ¹⁹F*) | Synthetic | β‑decay and γ‑spectroscopy studies | Evaluated intensity pattern compiled. (ChemLin) |
| ²⁰O | 8 | 20 | Unstable | 13.51 s | β⁻ (100%) | ²⁰F | β⁻ | Synthetic; rare cluster decay product | Structure & decay studies | Well‑established t½. (Periodic Table, KAERI Nuclear Data Center) |
| ²¹O | 8 | 21 | Unstable | 3.42 s | β⁻ → ²¹F | ²¹F | β⁻ | Synthetic | β‑decay spectroscopy | Recommended t½ ≈ 3.42 s. (KAERI Nuclear Data Center) |
| ²²O | 8 | 22 | Unstable | 2.25 s | β⁻ (> ~78%); β⁻n (< ~22%) | ²²F; ²¹F + n | β⁻; delayed n | Synthetic | β‑delayed‑neutron emission studies | Branching fractions compiled. (KAERI Nuclear Data Center, ChemLin) |
| ²³O | 8 | 23 | Unstable | 82 ms | β⁻ (≈ 69%); β⁻n (≈ 31%) | ²³F; ²²F + n | β⁻; delayed n | Synthetic | Dripline & delayed‑n benchmarks | KAERI/ENSDF agree within uncertainties. (Periodic Table, KAERI Nuclear Data Center) |
| ²⁴O | 8 | 24 | Unstable | 77.4 ms | β⁻ (≈ 57%); β⁻n (≈ 43%) | ²⁴F; ²³F + n | β⁻; delayed n | Synthetic | Doubly‑magic‑like N=16 shell effects | Heaviest particle‑bound O; short‑lived β‑emitter. (ChemLin) |
| ²⁵O | 8 | 25 | Unstable (unbound) | prompt ~10⁻²¹ s | n emission | ²⁴O + n | neutrons | Synthetic | Research (beyond drip line) | Ground state unbound to n emission. (Physical Review Link) |
| ²⁶O | 8 | 26 | Unstable (unbound) | ≈ 4.5 ps | 2n emission | ²⁴O + 2n | neutrons (2n) | Synthetic | Two‑neutron radioactivity case study | Barely unbound; lifetime measured in ps range. (arXiv, Physical Review Link) |
| ²⁷O | 8 | 27 | Unstable (unbound) | ~10⁻²¹ s (resonance) | 3n emission | ²⁴O + 3n | neutrons | Synthetic | Research (4N=magic tests) | Observed via decay to ²⁴O+3n. (Nature) |
| ²⁸O | 8 | 28 | Unstable (unbound) | ~10⁻²¹ s (resonance) | 4n emission | ²⁴O + 4n | neutrons | Synthetic | Research (doubly‑magic test of N=20) | First observation showed it is unbound. (Nature, Oak Ridge National Laboratory, The Department of Energy’s Energy.gov) |
Radiation key: β⁺/EC (positron/electron capture) → annihilation γ (511 keV); β⁻ (electron); n/2n/3n/4n (prompt neutron emission from unbound states); 2p (two‑proton emission from proton‑unbound states).
Totals — Oxygen
- Stable: 3 (¹⁶O, ¹⁷O, ¹⁸O)
- Unstable: 15 (¹¹–¹⁵O, ¹⁹–²⁴O, ²⁵–²⁸O)
- Total isotopes: 18
Running cumulative totals (up to Z = 8)
- Cumulative total isotopes: 98 (H: 7 • He: 8 • Li: 10 • Be: 11 • B: 15 • C: 14 • N: 15 • O: 18)
- Cumulative stable: 16 (H: 2 • He: 2 • Li: 2 • Be: 1 • B: 2 • C: 2 • N: 2 • O: 3)
- Cumulative unstable: 82
Sources
- Authoritative datasets / look‑ups: IAEA LiveChart of Nuclides (ENSDF backbone) — isotope properties and decay‑mode definitions. (Nuclear Data Services)
- Light, proton‑rich oxygen: ¹¹O first observation as an unbound 2p emitter (2019, PRL); ¹²O 2p emission (R‑matrix/exp. studies). (Physical Review Link, actaphys.uj.edu.pl)
- Precision β⁺ half‑lives: ¹³O (8.58 ms) consolidated; ¹⁴O (70.619 s) high‑precision evaluations; ¹⁵O (122.24 s) in medical radionuclide production literature. (ChemLin, Atrium, arXiv, Journal of Nuclear Medicine)
- β⁻ chain to fluorine (neutron‑rich): ¹⁹O (26.470 s), ²⁰O (13.51 s), ²¹O (3.42 s), ²²O (2.25 s) with delayed‑n branches; ²³O (82 ms, β/βn); ²⁴O (77.4 ms, β/βn). (ChemLin, Periodic Table, KAERI Nuclear Data Center)
- Beyond the neutron drip line: ²⁵O/²⁶O unbound; ²⁶O ps‑scale 2n radioactivity (PRL 2013; RIKEN follow‑up “barely unbound”); ²⁷O, ²⁸O first observation and 3n/4n emission to ²⁴O (Nature 2023; ORNL/DOE explainer). (Physical Review Link, Nature, Oak Ridge National Laboratory, The Department of Energy’s Energy.gov)
- Applications of stable isotopes: ¹⁷O for NMR/MRI; ¹⁸O in hydrology & paleoclimate (δ¹⁸O); ¹⁸O→¹⁸F PET production via ¹⁸O(p,n)¹⁸F. (NCBI, RSNA Publications, USGS, U.S. Geological Survey, PMC)
Next: Fluorine (Z = 9)