Notation. Nuclides are written with the mass number as a left superscript (e.g., ²⁶⁶Lr).
Columns. Stable? — Lawrencium has no stable isotopes. Half-lives = evaluated values; # = extrapolated/systematics. Decay → daughter(s) shows main branches. Radiation: α, β⁻, SF (spontaneous fission), EC (electron capture). Origin: all isotopes are synthetic. Uses: R research only.
Primary data spine: evaluated Isotopes of lawrencium (ENSDF/NUBASE 2020).
Table — ground states
| Nuclide | Z | A | Stable? | Half-life | Decay → daughter(s) | Radiation | Origin | Notes & Uses |
|---|---|---|---|---|---|---|---|---|
| ²⁵²Lr | 103 | 252 | No | ~0.36 ms | α → ²⁴⁸Md | α | Fusion-evap. | R. |
| ²⁵³Lr | 103 | 253 | No | 0.36 s | α → ²⁴⁹Md | α | Synthetic | R. |
| ²⁵⁴Lr | 103 | 254 | No | 0.45 s | α → ²⁵⁰Md | α | Synthetic | R. |
| ²⁵⁵Lr | 103 | 255 | No | 0.7 s | α → ²⁵¹Md | α | Synthetic | R. |
| ²⁵⁶Lr | 103 | 256 | No | 27 s | α → ²⁵²Md | α | Synthetic | R. |
| ²⁵⁷Lr | 103 | 257 | No | 0.65 s | α → ²⁵³Md | α | Synthetic | R. |
| ²⁵⁸Lr | 103 | 258 | No | 4.2 s | α → ²⁵⁴Md | α | Synthetic | R. |
| ²⁵⁹Lr | 103 | 259 | No | 6.2 s | α → ²⁵⁵Md; SF minor | α; SF | Synthetic | R. |
| ²⁶⁰Lr | 103 | 260 | No | 2.7 min | α → ²⁵⁶Md | α | Synthetic | R. |
| ²⁶¹Lr | 103 | 261 | No | 44 min | α → ²⁵⁷Md | α | Synthetic | R. |
| ²⁶²Lr | 103 | 262 | No | 3.6 h | α → ²⁵⁸Md | α | Synthetic | Longest-lived Lr isotope used in chemistry. |
| ²⁶³Lr | 103 | 263 | No | 10 min | α → ²⁵⁹Md | α | Synthetic | R. |
| ²⁶⁴Lr | 103 | 264 | No | 3.2 h | SF / α → ²⁶⁰Md | SF; α | Synthetic | Research on fission properties. |
| ²⁶⁵Lr | 103 | 265 | No | 2.8 min | α → ²⁶¹Md | α | Synthetic | R. |
| ²⁶⁶Lr | 103 | 266 | No | 11 h | α → ²⁶²Md | α | Synthetic | Longest-lived isotope; supports Lr chemistry experiments. |
Natural isotopes of lawrencium
- None.
- All isotopes are synthetic, produced in particle accelerators (via fusion of actinides with light ions such as B, C, N, O).
Applied & research highlights
- ²⁶²Lr (3.6 h) and ²⁶⁶Lr (11 h): longest-lived isotopes; allow tracer-scale chemistry experiments.
- Lawrencium’s electron configuration is anomalous — [Rn]5f¹⁴7s²7p¹ — placing it at the end of the actinide series, not as a typical d-block element.
- Experiments confirmed Lr³⁺ as its dominant oxidation state, aligning with actinide chemistry trends.
- No industrial or medical use — only fundamental nuclear and chemical research.
Totals — Lawrencium (Z = 103)
- Ground-state isotopes listed: 15 (A = 252–266).
- Stable: 0.
- Unstable: 15.
Running cumulative totals (through Lr):
From No ledger: ≥ 3 183 total, 252 stable, ≥ 2 930 unstable.
Add Lr (+15 total, +0 stable, +15 unstable) → ≥ 3 198 total, 252 stable, ≥ 2 945 unstable.
Sources
- Isotopic list (A = 252–266): Isotopes of lawrencium (ENSDF/NUBASE 2020).
- Lr discovery (1961, Berkeley; confirmed Dubna 1965): actinide history references.
- Chemistry experiments with ²⁶²Lr, ²⁶⁶Lr: tracer-level studies showing Lr³⁺ and anomalous 7p electron behavior.
Next element: Rutherfordium — Rf (Z = 104).