# Isotopen van nobelium

Het chemisch element nobelium (No), met een atoommassa van ongeveer 259 u, bezit geen stabiele isotopen en wordt dus geclassificeerd als radioactief element. De 12 radio-isotopen zijn onstabiel en hebben een relatief korte halfwaardetijd (de meeste minder dan een seconde).
In de natuur komt geen nobelium voor: alle isotopen zijn synthetisch bereid in een laboratorium. De eerste synthetische isotoop was $^{254}$No, in 1966.
De kortstlevende isotoop van nobelium is $^{250}$No, met een halfwaardetijd van ongeveer 5,7 microseconden. De langstlevende is $^{259}$No, met een halfwaardetijd van 58 minuten.

## Overzicht

| Nuclide | Z (p) | N (n) | Isotopische massa (u) | Halveringstijd | Radioactief verval | Kernspin |
| Kernspin |||
| $^{250}$No | 102 | 148 | 250,08751(22) | 5,7(8) µs | SS (99,95%) | 0$^+$ |
| $^{250}$No | 102 | 148 | 250,08751(22) | 5,7(8) µs | ${\ce {{^{250}_{102}No}->{^{246}_{100}Fm}+\,_{2}^{4}\alpha }}$ (0,05%) | 0$^+$ |
| $^{250}$No | 102 | 148 | 250,08751(22) | 5,7(8) µs | ${\ce {{^{250}_{102}No}->{^{250}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (2,5 × 10$^{−4}$%) | 0$^+$ |
| $^{251}$No | 102 | 149 | 251,08901(19) | 0,78(2) s | ${\ce {{^{251}_{102}No}->{^{247}_{100}Fm}+\,_{2}^{4}\alpha }}$ (89%) | 7/2$^+$ |
| $^{251}$No | 102 | 149 | 251,08901(19) | 0,78(2) s | SS (10%) | 7/2$^+$ |
| $^{251}$No | 102 | 149 | 251,08901(19) | 0,78(2) s | ${\ce {{^{251}_{102}No}->{^{251}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (1%) | 7/2$^+$ |
| $^{251m}$No | 110(180) keV | 110(180) keV | 110(180) keV | 1,7(10) s | | 9/2$^−$ |
| $^{252}$No | 102 | 150 | 252,088977(14) | 2,27(14) s | ${\ce {{^{252}_{102}No}->{^{248}_{100}Fm}+\,_{2}^{4}\alpha }}$ (73,09%) | 0$^+$ |
| $^{252}$No | 102 | 150 | 252,088977(14) | 2,27(14) s | SS (26,9%) | 0$^+$ |
| $^{252}$No | 102 | 150 | 252,088977(14) | 2,27(14) s | ${\ce {{^{252}_{102}No}->{^{252}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (1%) | 0$^+$ |
| $^{253}$No | 102 | 151 | 253,09068(11) | 1,62(15) min | ${\ce {{^{253}_{102}No}->{^{249}_{100}Fm}+\,_{2}^{4}\alpha }}$ (80%) | (9/2$^−$) |
| $^{253}$No | 102 | 151 | 253,09068(11) | 1,62(15) min | ${\ce {{^{253}_{102}No}->{^{253}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (20%) | (9/2$^−$) |
| $^{253}$No | 102 | 151 | 253,09068(11) | 1,62(15) min | SS (10$^{−3}$%) | (9/2$^−$) |
| $^{253m}$No | 129(19) keV | 129(19) keV | 129(19) keV | 31 µs | | 5/2$^+$ |
| $^{254}$No | 102 | 152 | 254,090955(19) | 51(10) s | ${\ce {{^{254}_{102}No}->{^{250}_{100}Fm}+\,_{2}^{4}\alpha }}$ (89,3%) | 0$^+$ |
| $^{254}$No | 102 | 152 | 254,090955(19) | 51(10) s | ${\ce {{^{254}_{102}No}->{^{254}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (10%) | 0$^+$ |
| $^{254}$No | 102 | 152 | 254,090955(19) | 51(10) s | SS (0,31%) | 0$^+$ |
| $^{254m}$No | 500(100) keV | 500(100) keV | 500(100) keV | 0,28(4) s | IT → 254102No (80%) | 0$^+$ |
| $^{254m}$No | 500(100) keV | 500(100) keV | 500(100) keV | 0,28(4) s | ${\ce {{^{254}_{102}No}->{^{250}_{100}Fm}+\,_{2}^{4}\alpha }}$ (20%) | 0$^+$ |
| $^{255}$No | 102 | 153 | 255,093241(11) | 3,1(2) min | ${\ce {{^{255}_{102}No}->{^{251}_{100}Fm}+\,_{2}^{4}\alpha }}$ (61,4%) | (1/2$^+$) |
| $^{255}$No | 102 | 153 | 255,093241(11) | 3,1(2) min | ${\ce {{^{255}_{102}No}->{^{255}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (38,6%) | (1/2$^+$) |
| $^{256}$No | 102 | 154 | 256,094283(8) | 2,91(5) s | ${\ce {{^{256}_{102}No}->{^{252}_{100}Fm}+\,_{2}^{4}\alpha }}$ (99,44%) | 0$^+$ |
| $^{256}$No | 102 | 154 | 256,094283(8) | 2,91(5) s | SS (0,55%) | 0$^+$ |
| $^{256}$No | 102 | 154 | 256,094283(8) | 2,91(5) s | ${\ce {{^{256}_{102}No}+{e^{-}}->{^{256}_{101}Md}+{\nu }_{e}}}$ (0,01%) | 0$^+$ |
| $^{257}$No | 102 | 155 | 257,096877(23) | 25(2) s | ${\ce {{^{257}_{102}No}->{^{253}_{100}Fm}+\,_{2}^{4}\alpha }}$ (99%) | (7/2$^+$) |
| $^{257}$No | 102 | 155 | 257,096877(23) | 25(2) s | ${\ce {{^{257}_{102}No}->{^{257}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (1%) | (7/2$^+$) |
| $^{258}$No | 102 | 156 | 258,09821(22) | 1,2(2) ms | SS (99,99%) | 0$^+$ |
| $^{258}$No | 102 | 156 | 258,09821(22) | 1,2(2) ms | ${\ce {{^{258}_{102}No}->{^{254}_{100}Fm}+\,_{2}^{4}\alpha }}$ (0,01%) | 0$^+$ |
| $^{258}$No | 102 | 156 | 258,09821(22) | 1,2(2) ms | ${\ce {{^{258}_{102}No}->{^{258}_{101}Md}+{e^{+}}+{\nu }_{e}}}$ (zelden) | 0$^+$ |
| $^{259}$No | 102 | 157 | 259,10103(11) | 58(5) min | ${\ce {{^{259}_{102}No}->{^{255}_{100}Fm}+\,_{2}^{4}\alpha }}$ (75%) | (9/2$^+$) |
| $^{259}$No | 102 | 157 | 259,10103(11) | 58(5) min | ${\ce {{^{259}_{102}No}+{e^{-}}->{^{259}_{101}Md}+{\nu }_{e}}}$ (25%) | (9/2$^+$) |
| $^{259}$No | 102 | 157 | 259,10103(11) | 58(5) min | SS (10%) | (9/2$^+$) |
| $^{260}$No | 102 | 158 | 260,10264(22) | 106(8) ms | SS | 0$^+$ |
| $^{262}$No | 102 | 160 | 262,10730(48) | ± 5 ms | SS | 0$^+$ |

## Overzicht van isotopen per element

* (en) R.B. Firestone, S.Y. Frank Chu & C.M. Baglin (1999) - Table of Isotopes (online versie van de cd-rom)
* (en) G. Audi, A.H. Wapstra, C. Thibault, J. Blachot & O. Bersillon (2003) - The NUBASE evaluation of nuclear and decay properties, Nuclear Physics A, 729, pp. 3-128
* (en) J.R. de Laeter, J.K. Böhlke, P. De Bièvre, H. Hidaka, H.S. Peiser, K.J.R. Rosman & P.D.P. Taylor (2003) - Atomic weights of the elements. Review 2000 (IUPAC Technical Report), Pure and Applied Chemistry, 75 (6), pp. 683–800
* (en) M.E. Wieser (2006) - Atomic weights of the elements 2005 (IUPAC Technical Report), Pure and Applied Chemistry, 78 (11), pp. 2051–2066
* (en) David R. Lide (2004) - CRC Handbook of Chemistry and Physics (85th ed.), hoofdstuk 11, CRC Press - ISBN 978-0849304859
$^{248}$No · $^{249}$No · $^{250}$No · $^{251}$No · $^{251m}$No · $^{252}$No · $^{253}$No · $^{253m}$No · $^{254}$No · $^{254m}$No · $^{255}$No · $^{256}$No · $^{257}$No · $^{258}$No · $^{259}$No · $^{260}$No · $^{261}$No · $^{262}$No · $^{263}$No · $^{264}$No