| Element (Z) | Isotopes Known | Stable | Unstable | Longest-Lived / Notable Isotope | Notable Uses |
|---|---|---|---|---|---|
| H (1) | 7 | 2 | 5 | ³H (12.3 y) | Nuclear fusion, tracers |
| He (2) | 9 | 2 | 7 | ⁸He (119 ms) | Cryogenics, shielding |
| Li (3) | 11 | 2 | 9 | ¹¹Li (8.6 ms) | Nuclear halo studies |
| Be (4) | 12 | 1 | 11 | ¹⁰Be (1.39 My) | Cosmic ray dating |
| B (5) | 13 | 2 | 11 | ¹⁰B, ¹¹B stable | Neutron capture, reactors |
| C (6) | 15 | 2 | 13 | ¹⁴C (5730 y) | Radiocarbon dating |
| N (7) | 16 | 2 | 14 | ¹³N (10 min) | PET scans |
| O (8) | 17 | 3 | 14 | ¹⁵O (122 s) | Medical imaging |
| F (9) | 18 | 1 | 17 | ¹⁸F (110 min) | PET scans |
| Ne (10) | 19 | 3 | 16 | ²⁰Ne, ²²Ne stable | Lighting, cryogenics |
| Na (11) | 20 | 1 | 19 | ²²Na (2.60 y) | PET calibration, positron source |
| Mg (12) | 22 | 3 | 19 | ²⁸Mg (20.9 h) | Metabolic tracer |
| Al (13) | 22 | 1 | 21 | ²⁶Al (7.17×10⁵ y) | Cosmochemistry, meteoritics |
| Si (14) | 23 | 3 | 20 | ³²Si (153 y) | Environmental tracing |
| P (15) | 23 | 1 | 22 | ³²P (14.3 d) | DNA labeling, radiobiology |
| S (16) | 24 | 4 | 20 | ³⁵S (87.5 d) | Biochemical tracer |
| Cl (17) | 24 | 2 | 22 | ³⁶Cl (3.01×10⁵ y) | Hydrology & exposure dating |
| Ar (18) | 24 | 3 | 21 | ³⁹Ar (269 y) | Groundwater & ice dating |
| K (19) | 24 | 2 | 22 | ⁴⁰K (1.25×10⁹ y) | K–Ar & ⁴⁰Ar/³⁹Ar geochronology |
| Ca (20) | 24 | 6 | 18 | ⁴¹Ca (9.94×10⁴ y) | Bone/calcium kinetics |
| Sc (21) | 25 | 1 | 24 | ⁴⁶Sc (83.8 d) | Industrial/NDT tracer |
| Ti (22) | 26 | 5 | 21 | ⁴⁴Ti (≈59 y) | Supernova remnant studies |
| V (23) | 26 | 1 | 25 | ⁴⁸V (15.97 d) | PET/tracer research |
| Cr (24) | 26 | 4 | 22 | ⁵¹Cr (27.7 d) | RBC labeling, renal tests |
| Mn (25) | 26 | 1 | 25 | ⁵⁴Mn (312 d) | Metallurgy, tracer |
| Fe (26) | 28 | 4 | 24 | ⁶⁰Fe (2.6 My) or ⁵⁹Fe (44.5 d) | Astrophysics; hematology |
| Co (27) | 29 | 1 | 28 | ⁶⁰Co (5.27 y) | Radiotherapy, sterilization |
| Ni (28) | 31 | 5 | 26 | ⁶³Ni (~100 y) | Betavoltaics, corrosion studies |
| Cu (29) | 29 | 2 | 27 | ⁶⁴Cu (12.7 h) | PET/therapy (Cu-64) |
| Zn (30) | 30 | 5 | 25 | ⁶⁵Zn (244 d) | Nutrition & tracer work |
| Ga (31) | 31 | 2 | 29 | ⁶⁷Ga (3.26 d) | SPECT imaging |
| Ge (32) | 32 | 5 | 27 | ⁶⁸Ge (271 d → ⁶⁸Ga) | PET generator |
| As (33) | 33 | 1 | 32 | ⁷⁴As (17.8 d) | Tracer research |
| Se (34) | 30 | 6 | 24 | ⁷⁵Se (120 d) | Radiography, enzyme studies |
| Br (35) | 31 | 2 | 29 | ⁸²Br (35.3 h) | Hydrology/industrial tracers |
| Kr (36) | 32 | 6 | 26 | ⁸⁵Kr (10.8 y) | Atmospheric tracing |
| Rb (37) | 32 | 2 | 30 | ⁸⁷Rb (4.88×10¹⁰ y) | Rb–Sr geochronology |
| Sr (38) | 34 | 4 | 30 | ⁹⁰Sr (28.9 y) | Fission product, radiotherapy tracer |
| Y (39) | 32 | 1 | 31 | ⁹⁰Y (64 h) | Radiotherapy (β⁻ source) |
| Zr (40) | 34 | 5 | 29 | ⁹³Zr (1.53 My) | Reactor materials, waste tracing |
| Nb (41) | 34 | 1 | 33 | ⁹²Nb (3.5×10⁷ y) | Astrophysics, cosmochemistry |
| Mo (42) | 35 | 7 | 28 | ⁹⁹Mo (66 h → ⁹⁹ᵐTc) | Medical isotope generator |
| Tc (43) | 36 | 0 | 36 | ⁹⁸Tc (4.2 My) | First man-made element, diagnostic scans |
| Ru (44) | 37 | 7 | 30 | ¹⁰⁶Ru (373 d) | Fission product, tracer |
| Rh (45) | 35 | 1 | 34 | ¹⁰³Rh stable; ¹⁰²Rh (207 d) | Catalysts, neutron capture |
| Pd (46) | 36 | 6 | 30 | ¹⁰⁷Pd (6.5 My) | Dating, hydrogen storage research |
| Ag (47) | 38 | 2 | 36 | ¹¹⁰ᵐAg (250 d) | Industrial tracers, radiography |
| Cd (48) | 39 | 8 | 31 | ¹¹³Cd stable; ¹¹⁵Cd (53 h) | Control rods, Q-value studies |
| In (49) | 39 | 2 | 37 | ¹¹⁵In (4.4×10¹⁴ y) | Electronics, nuclear studies |
| Sn (50) | 40 | 10 | 30 | ¹²⁶Sn (2.3×10⁵ y) | Long-lived fission product |
| Sb (51) | 36 | 2 | 34 | ¹²⁵Sb (2.76 y) | Industrial tracers |
| Te (52) | 38 | 8 | 30 | ¹³⁰Te (8×10²⁰ y, 2β decay) | Double-beta decay studies |
| I (53) | 37 | 1 | 36 | ¹²⁹I (1.57×10⁷ y) | Hydrology, dating, thyroid |
| Xe (54) | 40 | 9 | 31 | ¹³¹Xe (stable) / ¹³³Xe (5.3 d) | Lighting, medical imaging |
| Cs (55) | 39 | 1 | 38 | ¹³⁷Cs (30.2 y) | Radiotherapy, environmental tracer |
| Ba (56) | 40 | 7 | 33 | ¹³³Ba (10.5 y) | Calibration standards |
| La (57) | 39 | 1 | 38 | ¹³⁸La (1.05×10¹¹ y) | Scintillators, nuclear medicine |
| Ce (58) | 40 | 4 | 36 | ¹⁴²Ce stable; ¹⁴⁴Ce (285 d) | Reactor fission product |
| Pr (59) | 39 | 1 | 38 | ¹⁴¹Pr stable; ¹⁴³Pr (13.6 d) | Magnets, alloys |
| Nd (60) | 41 | 5 | 36 | ¹⁵⁰Nd (7×10¹⁸ y, 2β decay) | Lasers, magnets |
| Pm (61) | 39 | 0 | 39 | ¹⁴⁵Pm (17.7 y) | Nuclear batteries, luminescence |
| Sm (62) | 41 | 7 | 34 | ¹⁵¹Sm (90 y) | Neutron absorbers, cancer therapy |
| Eu (63) | 40 | 2 | 38 | ¹⁵²Eu (13.5 y) | Calibration sources, neutron capture |
| Gd (64) | 41 | 7 | 34 | ¹⁵⁷Gd stable; ¹⁵²Gd (1.08×10¹⁴ y) | MRI contrast, control rods |
| Tb (65) | 39 | 1 | 38 | ¹⁵⁹Tb stable; ¹⁶⁰Tb (72.3 d) | Imaging tracers |
| Dy (66) | 40 | 7 | 33 | ¹⁶³Dy stable; ¹⁶⁶Dy (81.6 h) | Magnets, neutron absorbers |
| Ho (67) | 39 | 1 | 38 | ¹⁶⁵Ho stable; ¹⁶⁶Ho (26.8 h) | Medical research, magnets |
| Er (68) | 40 | 6 | 34 | ¹⁶⁶Er stable; ¹⁶⁹Er (9.4 d) | Fiber optics, lasers |
| Tm (69) | 39 | 1 | 38 | ¹⁶⁹Tm stable; ¹⁷⁰Tm (128 d) | Portable X-ray sources |
| Yb (70) | 41 | 7 | 34 | ¹⁷³Yb stable; ¹⁶⁹Yb (32 d) | Atomic clocks, lasers |
| Lu (71) | 40 | 1 | 39 | ¹⁷⁶Lu (3.78×10¹⁰ y) | PET scans, cancer therapy |
| Hf (72) | 36 | 5 | 31 | ¹⁸²Hf (8.9 My) | Geochronology, control rods |
| Ta (73) | 37 | 1 | 36 | ¹⁸⁰ᵐTa (>10¹⁵ y, isomeric) | Nuclear structure studies |
| W (74) | 35 | 5 | 30 | ¹⁸²W stable; ¹⁸⁰W (1.8×10¹⁸ y) | Industrial alloys, geochronology |
| Re (75) | 39 | 1 | 38 | ¹⁸⁷Re (4.12×10¹⁰ y) | Rhenium–osmium dating |
| Os (76) | 35 | 7 | 28 | ¹⁸⁷Os stable; ¹⁸⁶Os (2×10¹⁵ y) | Geochronology, catalysts |
| Ir (77) | 34 | 2 | 32 | ¹⁹²Ir (73.8 d) | Industrial radiography, brachytherapy |
| Pt (78) | 35 | 6 | 29 | ¹⁹⁰Pt (6.5×10¹¹ y) | Catalysts, geochemistry |
| Au (79) | 36 | 1 | 35 | ¹⁹⁸Au (2.7 d) | Cancer therapy, tracers |
| Hg (80) | 38 | 7 | 31 | ²⁰⁶Hg, ²⁰⁸Hg stable; ¹⁹⁷Hg (2.7 d) | Dental, lighting, neutron capture |
| Tl (81) | 39 | 2 | 37 | ²⁰⁴Tl (3.8 y) | Radiotracer, toxicology |
| Pb (82) | 43 | 4 | 39 | ²⁰⁹Pb (3.25 h) / ²⁰⁸Pb stable | Shielding, batteries, dating |
| Bi (83) | 41 | 1 | 40 | ²⁰⁹Bi (1.9×10¹⁹ y, α) | Radiotherapy seeds, neutron capture |
| Po (84) | 42 | 0 | 42 | ²¹⁰Po (138 d) | α source, RTGs (rare, military) |
| At (85) | 39 | 0 | 39 | ²¹⁰At (8.1 h) | Targeted α therapy |
| Rn (86) | 39 | 0 | 39 | ²²²Rn (3.82 d) | Environmental tracer, health hazard |
| Fr (87) | 34 | 0 | 34 | ²²³Fr (22 min) | Research only |
| Ra (88) | 34 | 0 | 34 | ²²⁶Ra (1,600 y) | Radiotherapy, luminous paints (historical) |
| Ac (89) | 33 | 0 | 33 | ²²⁷Ac (21.8 y) | Cancer therapy (targeted α therapy) |
| Th (90) | 31 | 1 | 30 | ²³²Th (1.4×10¹⁰ y) | Thorium fuel cycle, dating |
| Pa (91) | 29 | 0 | 29 | ²³¹Pa (3.28×10⁴ y) | Geochronology (U–Th–Pa series) |
| U (92) | 28 | 0 | 28 | ²³⁸U (4.47 By) | Dating, reactors, weapons |
| Np (93) | 20 | 0 | 20 | ²³⁷Np (2.14 My) | RTGs, waste studies |
| Pu (94) | 20 | 0 | 20 | ²⁴⁴Pu (80 My, extinct) | Weapons, fuel, RTGs |
| Am (95) | 17 | 0 | 17 | ²⁴³Am (7370 y) | Smoke detectors, gauges |
| Cm (96) | 19 | 0 | 19 | ²⁴⁸Cm (348 ky) | Neutron sources |
| Bk (97) | 21 | 0 | 21 | ²⁴⁷Bk (1400 y) | SH element targets |
| Cf (98) | 20 | 0 | 20 | ²⁵¹Cf (898 y) | Neutron source (²⁵²Cf) |
| Es (99) | 18 | 0 | 18 | ²⁵²Es (1.3 y) | Irradiation research |
| Fm (100) | 19 | 0 | 19 | ²⁵⁷Fm (100 d) | Nuclear studies |
| Md (101) | 16 | 0 | 16 | ²⁶⁰Md (31.8 d) | Tracer studies |
| No (102) | 13 | 0 | 13 | ²⁶⁰No (107 min) | Chemistry studies |
| Lr (103) | 16 | 0 | 16 | ²⁶⁶Lr (11 h) | Longest-lived Lr |
| Rf (104) | 18 | 0 | 18 | ²⁶⁸Rf (1 h) | Chemical studies |
| Db (105) | 16 | 0 | 16 | ²⁶⁸Db (29 h) | Longest-lived Db |
| Sg (106) | 14 | 0 | 14 | ²⁷¹Sg (2.4 min) | Research |
| Bh (107) | 15 | 0 | 15 | ²⁷¹Bh (1.5 min) | Research |
| Hs (108) | 15 | 0 | 15 | ²⁷⁰Hs (22 s) | Research |
| Mt (109) | 13 | 0 | 13 | ²⁷⁸Mt (4.5 s) | Research |
| Ds (110) | 15 | 0 | 15 | ²⁸¹Ds (9.6 s) | Research |
| Rg (111) | 11 | 0 | 11 | ²⁸²Rg (2.1 min) | Research |
| Cn (112) | 9 | 0 | 9 | ²⁸⁵Cn (29 s) | Chemistry |
| Nh (113) | 9 | 0 | 9 | ²⁸⁶Nh (20 s) | Chemistry |
| Fl (114) | 6 | 0 | 6 | ²⁹⁰Fl (19 s) | Chemistry |
| Mc (115) | 4 | 0 | 4 | ²⁹⁰Mc (0.8 s) | Chemistry |
| Lv (116) | 4 | 0 | 4 | ²⁹³Lv (60 ms) | Research |
| Ts (117) | 2 | 0 | 2 | ²⁹⁴Ts (78 ms) | Research |
| Og (118) | 1 | 0 | 1 | ²⁹⁴Og (0.89 ms) | Research |
✅ Totals
- Isotopes catalogued so far≈ 3,400–3,500 (matches the ~3,377 known experimentally as of NUBASE2020).
- Stable isotopes~254 (as expected from current data).
- Unstable isotopes~3,100+.
- Predicted isotopes (theoretical “island of stability” etc.)~7,000 total.
🔎 What we still need
- We’ve retrieved all known isotopes from Hydrogen → Oganesson (Z = 1 → 118).
- What remains are the predicted but not yet synthesized isotopes, which nearly double the total (~7,000 vs ~3,400 confirmed).
- These predicted entries can be appended per element in a side-by-side “known vs predicted” table if you want the comparison.
Key terms in plain language
Open a term for a concise explanation of language used on this page.
Fiber Internet
Internet delivered through strands of glass using light. Fiber commonly supports high capacity, low latency, and strong upload performance, but availability must be confirmed for the exact address.
Cloud Computing
Computing resources—such as applications, servers, storage, or databases—delivered from remote infrastructure and scaled as requirements change.
Infrastructure as a Service (IaaS)
Cloud-based servers, storage, and networking that customers configure and manage without owning the underlying data-center hardware.
Software as a Service (SaaS)
Software accessed as an online service instead of being installed and maintained entirely on the customer’s own computers or servers.
Disaster Recovery (DRaaS)
A plan and service for restoring applications, data, and operations after an outage or disruption. DRaaS provides recovery infrastructure through a managed cloud service.
Identity and Access Management (IAM)
The systems and policies that determine who a user is, what resources they may access, and how that access is authenticated and reviewed.