Isotopes
Twelve radioisotopes of nobelium have been characterized, with the most stable being 259No with a half-life of 58 minutes. Longer half-lives are expected for the as-yet-unknown 261No and 263No. An isomeric level has been found in 253No and K-isomers have been found in 250No, 252No and 254No to date.
- Chronology of isotope discovery
| Isotope | Year discovered | Discovery reaction |
|---|---|---|
| 250Nom | 2001 | 204Pb(48Ca,2n) |
| 250Nog | 2006 | 204Pb(48Ca,2n) |
| 251No | 1967 | 244Cm(12C,5n) |
| 252Nog | 1959 | 244Cm(12C,4n) |
| 252Nom | ~2002 | 206Pb(48Ca,2n) |
| 253Nog | 1967 | 242Pu(16O,5n),239Pu(18O,4n) |
| 253Nom | 1971 | 249Cf(12C,4n) |
| 254Nog | 1966 | 243Am(15N,4n) |
| 254Nom1 | 1967? | 246Cm(13C,5n),246Cm(12C,4n) |
| 254Nom2 | ~2003 | 208Pb(48Ca,2n) |
| 255No | 1967 | 246Cm(13C,4n),248Cm(12C,5n) |
| 256No | 1967 | 248Cm(12C,4n),248Cm(13C,5n) |
| 257No | 1961?, 1967 | 248Cm(13C,4n) |
| 258No | 1967 | 248Cm(13C,3n) |
| 259No | 1973 | 248Cm(18O,α3n) |
| 260No | ? | 254Es + 22Ne,18O,13C - transfer |
| 261No | unknown | |
| 262No | 1988 | 254Es + 22Ne - transfer (EC of 262Lr) |
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