Notation: mass number shown as a left superscript (e.g., ¹⁴C).
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 |
|---|---|---|---|---|---|---|---|---|---|---|
| ⁸C | 6 | 8 | Unstable (unbound) | ≈ 3.5 zs (Γ≈230 keV) | 2p emission | ⁶Be (→ ⁴He + 2p) | protons (no α/β/γ) | Synthetic | Research (proton‑dripline; multi‑p emission) | Net: ⁸C → ⁴He + 4p. (Wikipedia) |
| ⁹C | 6 | 9 | Unstable | 126.5 ms | β⁺ (≈54%); β⁺α (≈38%); β⁺p (≈7.5%) | ⁹B (unbound → p+2α); ⁵Li; ⁸Be | β⁺; annihilation γ (511 keV); α; p | Synthetic | Research (β‑delayed particle studies) | Multiparticle β‑delayed branches well‑characterized. (Wikipedia) |
| ¹⁰C | 6 | 10 | Unstable | 19.301 s | β⁺ | ¹⁰B | β⁺; annihilation γ | Synthetic | Research; PET method development | — (Wikipedia) |
| ¹¹C | 6 | 11 | Unstable | 20.340 min | β⁺ (EC ≈ 0.2%) | ¹¹B | β⁺; annihilation γ | Synthetic (cyclotron) | Medical (PET radiotracers) | Produced as ¹¹CO₂; standard PET label. (Wikipedia, IAEA Publications, PMC) |
| ¹²C | 6 | 12 | Stable | stable | — | — | — | Natural | Reference mass standard; materials (graphite/diamond) | 1 Da defined as 1/12 of ¹²C. (Wikipedia) |
| ¹³C | 6 | 13 | Stable | stable | — | — | — | Natural | NMR & isotopic labeling (metabolic flux, breath tests) | Widely used for ¹³C‑NMR. (PMC) |
| ¹⁴C | 6 | 14 | Unstable | 5.70×10³ y | β⁻ | ¹⁴N | β⁻ (no significant γ) | Natural trace (cosmogenic) & Synthetic | Radiocarbon dating; tracers | Canonical radiocarbon half‑life. (NuclData) |
| ¹⁵C | 6 | 15 | Unstable | 2.449 s | β⁻ | ¹⁵N | β⁻ | Synthetic | Research (structure/halo systematics) | — (Wikipedia) |
| ¹⁶C | 6 | 16 | Unstable | 750 ms | β⁻n (≈99%); β⁻ (≈1%) | ¹⁵N; ¹⁶N | β⁻; delayed n | Synthetic | Research (β‑delayed‑n emission) | — (Wikipedia) |
| ¹⁷C | 6 | 17 | Unstable | 193 ms | β⁻ (≈71.6%); β⁻n (≈28.4%) | ¹⁷N; ¹⁶N | β⁻; delayed n | Synthetic | Research | — (Wikipedia) |
| ¹⁸C | 6 | 18 | Unstable | 92 ms | β⁻ (≈68.5%); β⁻n (≈31.5%) | ¹⁸N; ¹⁷N | β⁻; delayed n | Synthetic | Research | — (Wikipedia) |
| ¹⁹C | 6 | 19 | Unstable | 46.2 ms | β⁻n (≈47%); β⁻ (≈46%); β⁻2n (≈7%) | ¹⁸N; ¹⁹N; ¹⁷N | β⁻; delayed n | Synthetic | Halo‑nucleus research | ¹⁹C has one halo neutron. (Wikipedia) |
| ²⁰C | 6 | 20 | Unstable | 16 ms | β⁻n (≈70%); β⁻ (≥ 11%); β⁻2n (< 18.6%) | ¹⁹N; ²⁰N; ¹⁸N | β⁻; delayed n | Synthetic | Dripline/β‑delayed‑n studies | — (Wikipedia) |
| ²²C | 6 | 22 | Unstable | 6.2 ms | β⁻n (≈61%); β⁻2n (< 37%); β⁻ (> 2%) | ²¹N; ²⁰N; ²²N | β⁻; delayed n | Synthetic | Two‑neutron halo research | ²²C has two halo neutrons. (Wikipedia) |
Scope note: ²¹C is not experimentally confirmed (neutron‑unbound candidate) and is not counted above. (National Nuclear Data Center, CERN Document Server, ChemLin)
Totals — Carbon
- Stable: 2 (¹²C, ¹³C)
- Unstable: 12 (⁸–¹¹C, ¹⁴–²⁰C, ²²C)
- Total isotopes: 14
Running cumulative totals (up to Z = 6)
- Cumulative total isotopes: 65 (H: 7 • He: 8 • Li: 10 • Be: 11 • B: 15 • C: 14)
- Cumulative stable: 11 (H: 2 • He: 2 • Li: 2 • Be: 1 • B: 2 • C: 2)
- Cumulative unstable: 54
Sources
- IAEA LiveChart of Nuclides / ENSDF — authoritative half‑lives & decay modes; data definitions (Γ ↔ t½). (Nuclear Data Services)
- NNDC NuDat 3 — ENSDF interface for ground‑state decay & branches. (National Nuclear Data Center)
- Isotopes of carbon — consolidated table of ⁸–²²C half‑lives, modes & branches; notes on halo character (¹⁹C, ²²C) and ¹²C mass standard. (Wikipedia)
- TUNL Ground‑State Decay: ¹⁴C — evaluated ¹⁴C β⁻ half‑life used for radiocarbon dating. (NuclData)
- IAEA TRS‑465; reviews on PET radionuclides — ¹¹C (20.3–20.4 min) widely used as a PET label. (IAEA Publications, PMC)
Next: Nitrogen (Z = 7)