This ledger shows for each element:
- Known isotopes (experimentally observed)
- Stable (strict) isotopes (per IUPAC)
- Unstable isotopes (= Known − Stable)
- Predicted isotopes (scaled to Neufcourt et al. 2020: 7,759 total)
- Gap (Predicted − Known)
- Representative γ energy (keV) — a key line for environmental/medical/industrial monitoring
- Resonant frequency (Hz) — photon frequency corresponding to the γ line
Totals
- Total elements: 118
- Known isotopes: 3,269
- Stable isotopes (strict): 273
- Unstable isotopes: 2,996
- Predicted isotopes: 7,759
- Total Gap: 4,490
Table (Z = 1–118, excerpt)
| Z | Element | Known | Stable | Unstable | Predicted | Gap | Rep. γ (keV) | Resonant f (Hz) |
|---|---|---|---|---|---|---|---|---|
| 1 | H | 7 | 2 | 5 | 17 | 10 | — | — |
| 2 | He | 9 | 2 | 7 | 21 | 12 | — | — |
| 3 | Li | 11 | 2 | 9 | 26 | 15 | — | — |
| 4 | Be | 12 | 1 | 11 | 28 | 16 | — | — |
| 5 | B | 13 | 2 | 11 | 31 | 18 | — | — |
| 6 | C | 15 | 2 | 13 | 36 | 21 | — | — |
| 7 | N | 16 | 2 | 14 | 38 | 22 | — | — |
| 8 | O | 17 | 3 | 14 | 40 | 23 | — | — |
| 9 | F | 18 | 1 | 17 | 43 | 25 | — | — |
| 10 | Ne | 19 | 3 | 16 | 45 | 26 | — | — |
| 11 | Na | 20 | 1 | 19 | 47 | 27 | 1274.5 | 3.08×10²⁰ |
| 12 | Mg | 22 | 3 | 19 | 52 | 30 | — | — |
| 13 | Al | 22 | 1 | 21 | 52 | 30 | — | — |
| 14 | Si | 23 | 3 | 20 | 55 | 32 | — | — |
| 15 | P | 23 | 1 | 22 | 55 | 32 | — | — |
| 16 | S | 24 | 4 | 20 | 57 | 33 | — | — |
| 17 | Cl | 24 | 2 | 22 | 57 | 33 | — | — |
| 18 | Ar | 24 | 3 | 21 | 57 | 33 | 1293.6 | 3.13×10²⁰ |
| 19 | K | 24 | 2 | 22 | 57 | 33 | 1460.8 | 3.53×10²⁰ |
| 20 | Ca | 24 | 6 | 18 | 57 | 33 | — | — |
| … | … | … | … | … | … | … | … | … |
| 53 | I | 37 | 1 | 36 | 88 | 51 | 364.5 | 8.81×10¹⁹ |
| 54 | Xe | 40 | 9 | 31 | 95 | 55 | 81 | 1.96×10¹⁹ |
| 55 | Cs | 39 | 1 | 38 | 93 | 54 | 661.7 | 1.60×10²⁰ |
| 60 | Nd | 41 | 5 | 36 | 97 | 56 | — | — |
| 62 | Sm | 41 | 7 | 34 | 97 | 56 | 333 | 8.05×10¹⁹ |
| 64 | Gd | 41 | 7 | 34 | 97 | 56 | 1596 | 3.86×10²⁰ |
| 79 | Au | 36 | 1 | 35 | 85 | 49 | 411 | 9.94×10¹⁹ |
| 80 | Hg | 38 | 7 | 31 | 90 | 52 | 279 | 6.73×10¹⁹ |
| 81 | Tl | 39 | 2 | 37 | 93 | 54 | 2614.5 | 6.32×10²⁰ |
| 82 | Pb | 43 | 4 | 39 | 102 | 59 | 351.9 | 8.51×10¹⁹ |
| 83 | Bi | 41 | 0 | 41 | 97 | 56 | 609.3 | 1.47×10²⁰ |
| 92 | U | 28 | 0 | 28 | 66 | 38 | 1001 | 2.42×10²⁰ |
| 94 | Pu | 20 | 0 | 20 | 47 | 27 | 375 | 9.07×10¹⁹ |
| 137 | Cs | (see above) | 661.7 | 1.60×10²⁰ | ||||
| 131 | I | (see above) | 364.5 | 8.81×10¹⁹ |
Notes:
- “Rep. γ (keV)” is a single, prominent line per element (from a common isotope).
- “Resonant f (Hz)” is computed frequency ( f = E/h ).
- For α- or β-only emitters (e.g., ³H, ¹⁴C, ⁹⁰Sr), no γ line is listed.
- Noble gases (Ar, Kr, Xe, Rn) and halogens (I, Br) often matter atmospherically.
- Thorium/Uranium chains show γ signatures mainly via daughters (²¹⁴Pb, ²¹⁴Bi, ²⁰⁸Tl).