# Isotopen van mendelevium

Het chemisch element mendelevium (Md), met een atoommassa van ongeveer 258 u, bezit geen stabiele isotopen en wordt dus geclassificeerd als radioactief element. De 17 radio-isotopen zijn onstabiel en hebben een relatief korte halfwaardetijd (de meeste minder dan een uur).
In de natuur komt geen mendelevium voor: alle isotopen zijn synthetisch bereid in een laboratorium. De eerste synthetische isotoop was $^{256}$Md, in 1955.
De kortstlevende isotoop van mendelevium is $^{245}$Md, met een halfwaardetijd van ongeveer 0,9 milliseconden. De langstlevende is $^{258}$Md, met een halfwaardetijd van 51,5 dagen.

## Overzicht

| Nuclide | Z (p) | N (n) | Isotopische massa (u) | Halveringstijd | Radioactief verval | Kernspin |
| Kernspin |||
| $^{245}$Md | 101 | 144 | 245,08083(35) | 0,90(25) ms | SS | (1/2$^−$) |
| $^{245}$Md | 101 | 144 | 245,08083(35) | 0,90(25) ms | ${\ce {{^{245}_{101}Md}->{^{241}_{99}Es}+\,_{2}^{4}\alpha }}$ (zelden) | (1/2$^−$) |
| $^{245m}$Md | 200(100) keV | 200(100) keV | 200(100) keV | 400(200) ms | ${\ce {{^{245m}_{101}Md}->{^{241}_{99}Es}+\,_{2}^{4}\alpha }}$ | (7/2$^+$) |
| $^{245m}$Md | 200(100) keV | 200(100) keV | 200(100) keV | 400(200) ms | ${\ce {{^{245}_{101}Md}->{^{245}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (zelden) | (7/2$^+$) |
| $^{246}$Md | 101 | 145 | 246,08189(35) | 1,0(4) s | ${\ce {{^{246}_{101}Md}->{^{242}_{99}Es}+\,_{2}^{4}\alpha }}$ | |
| $^{246}$Md | 101 | 145 | 246,08189(35) | 1,0(4) s | ${\ce {{^{246}_{101}Md}->{^{246}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (zelden) | |
| $^{247}$Md | 101 | 146 | 247,08164(35) | 1,12(22) s | SS | 1/2$^−$ |
| $^{247}$Md | 101 | 146 | 247,08164(35) | 1,12(22) s | ${\ce {{^{247}_{101}Md}->{^{243}_{99}Es}+\,_{2}^{4}\alpha }}$ (zelden) | 1/2$^−$ |
| $^{247m}$Md | | | | ± 0,2 s | ${\ce {{^{247m}_{101}Md}->{^{243}_{99}Es}+\,_{2}^{4}\alpha }}$ (99,99%) | |
| $^{247m}$Md | | | | ± 0,2 s | SS (10$^{−4}$%) | |
| $^{248}$Md | 101 | 147 | 248,08282(26) | 7(3) s | ${\ce {{^{248}_{101}Md}->{^{248}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (80%) | |
| $^{248}$Md | 101 | 147 | 248,08282(26) | 7(3) s | ${\ce {{^{248}_{101}Md}->{^{244}_{99}Es}+\,_{2}^{4}\alpha }}$ (20%) | |
| $^{248}$Md | 101 | 147 | 248,08282(26) | 7(3) s | SS (0,05%) | |
| $^{249}$Md | 101 | 148 | 249,08301(24) | 24(4) s | ${\ce {{^{249}_{101}Md}->{^{245}_{99}Es}+\,_{2}^{4}\alpha }}$ (60%) | (7/2$^−$) |
| $^{249}$Md | 101 | 148 | 249,08301(24) | 24(4) s | ${\ce {{^{249}_{101}Md}->{^{249}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (40%) | (7/2$^−$) |
| $^{249m}$Md | 100(100) keV | 100(100) keV | 100(100) keV | 1,9(9) s | | (1/2$^−$) |
| $^{250}$Md | 101 | 149 | 250,08442(32) | 52(6) s | ${\ce {{^{250}_{101}Md}->{^{250}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (93%) | |
| $^{250}$Md | 101 | 149 | 250,08442(32) | 52(6) s | ${\ce {{^{250}_{101}Md}->{^{246}_{99}Es}+\,_{2}^{4}\alpha }}$(7%) | |
| $^{250}$Md | 101 | 149 | 250,08442(32) | 52(6) s | SS (0,02%) | |
| $^{251}$Md | 101 | 150 | 251,08484(22) | 4,0(5) min | ${\ce {{^{251}_{101}Md}->{^{251}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (90%) | 7/2$^−$ |
| $^{251}$Md | 101 | 150 | 251,08484(22) | 4,0(5) min | ${\ce {{^{251}_{101}Md}->{^{247}_{99}Es}+\,_{2}^{4}\alpha }}$ (10%) | 7/2$^−$ |
| $^{252}$Md | 101 | 151 | 252,08656(21) | 2,3(8) min | ${\ce {{^{252}_{101}Md}->{^{252}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (50%) | |
| $^{252}$Md | 101 | 151 | 252,08656(21) | 2,3(8) min | ${\ce {{^{252}_{101}Md}->{^{248}_{99}Es}+\,_{2}^{4}\alpha }}$ (50%) | |
| $^{253}$Md | 101 | 152 | 253,08728(22) | 12(8) min | ${\ce {{^{253}_{101}Md}->{^{253}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ | 7/2$^−$ |
| $^{253}$Md | 101 | 152 | 253,08728(22) | 12(8) min | ${\ce {{^{253}_{101}Md}->{^{249}_{99}Es}+\,_{2}^{4}\alpha }}$ | 7/2$^−$ |
| $^{254}$Md | 101 | 153 | 254,08966(11) | 10(3) min | ${\ce {{^{254}_{101}Md}->{^{254}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ | (0$^−$) |
| $^{254}$Md | 101 | 153 | 254,08966(11) | 10(3) min | ${\ce {{^{254}_{101}Md}->{^{250}_{99}Es}+\,_{2}^{4}\alpha }}$ (zelden) | (0$^−$) |
| $^{254m}$Md | 50(100) keV | 50(100) keV | 50(100) keV | 28(8) min | ${\ce {{^{254}_{101}Md}->{^{254}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ | (3$^−$) |
| $^{254m}$Md | 50(100) keV | 50(100) keV | 50(100) keV | 28(8) min | ${\ce {{^{254}_{101}Md}->{^{250}_{99}Es}+\,_{2}^{4}\alpha }}$ (zelden) | (3$^−$) |
| $^{255}$Md | 101 | 154 | 255,091083(7) | 27(2) min | ${\ce {{^{255}_{101}Md}->{^{255}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (92%) | (7/2$^−$) |
| $^{255}$Md | 101 | 154 | 255,091083(7) | 27(2) min | ${\ce {{^{255}_{101}Md}->{^{251}_{99}Es}+\,_{2}^{4}\alpha }}$ (8%) | (7/2$^−$) |
| $^{255}$Md | 101 | 154 | 255,091083(7) | 27(2) min | SS (0,15%) | (7/2$^−$) |
| $^{256}$Md | 101 | 155 | 256,09406(6) | 77(2) min | ${\ce {{^{256}_{101}Md}->{^{256}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (89%) | (1$^−$) |
| $^{256}$Md | 101 | 155 | 256,09406(6) | 77(2) min | ${\ce {{^{256}_{101}Md}->{^{252}_{99}Es}+\,_{2}^{4}\alpha }}$ (11%) | (1$^−$) |
| $^{257}$Md | 101 | 156 | 257,095541(3) | 5,52(5) uur | ${\ce {{^{257}_{101}Md}+{e^{-}}->{^{257}_{100}Fm}+{\nu }_{e}}}$ (84,8%) | (7/2$^−$) |
| $^{257}$Md | 101 | 156 | 257,095541(3) | 5,52(5) uur | ${\ce {{^{257}_{101}Md}->{^{253}_{99}Es}+\,_{2}^{4}\alpha }}$ (15,2%) | (7/2$^−$) |
| $^{257}$Md | 101 | 156 | 257,095541(3) | 5,52(5) uur | SS (1%) | (7/2$^−$) |
| $^{258}$Md | 101 | 157 | 258,098431(5) | 51,5(3) dagen | ${\ce {{^{258}_{101}Md}->{^{254}_{99}Es}+\,_{2}^{4}\alpha }}$ (99,99%) | (8$^−$) |
| $^{258}$Md | 101 | 157 | 258,098431(5) | 51,5(3) dagen | ${\ce {{^{258}_{101}Md}->{^{258}_{102}No}+{e^{-}}+{\bar {\nu }}_{e}}}$ (0,0015%) | (8$^−$) |
| $^{258}$Md | 101 | 157 | 258,098431(5) | 51,5(3) dagen | ${\ce {{^{258}_{101}Md}->{^{258}_{100}Fm}+{e^{+}}+{\nu }_{e}}}$ (0,0015%) | (8$^−$) |
| $^{258m}$Md | 0(200) keV | 0(200) keV | 0(200) keV | 57,0(9) min | ${\ce {{^{258}_{101}Md}+{e^{-}}->{^{258}_{100}Fm}+{\nu }_{e}}}$(70%) | 1$^−$ |
| $^{258m}$Md | 0(200) keV | 0(200) keV | 0(200) keV | 57,0(9) min | SS (20%) | 1$^−$ |
| $^{258m}$Md | 0(200) keV | 0(200) keV | 0(200) keV | 57,0(9) min | ${\ce {{^{258}_{101}Md}->{^{258}_{102}No}+{e^{-}}+{\bar {\nu }}_{e}}}$ (10%) | 1$^−$ |
| $^{258m}$Md | 0(200) keV | 0(200) keV | 0(200) keV | 57,0(9) min | ${\ce {{^{258}_{101}Md}->{^{254}_{99}Es}+\,_{2}^{4}\alpha }}$ (1,2%) | 1$^−$ |
| $^{259}$Md | 101 | 158 | 259,10051(22) | 1,60(6) uur | SS (98,7%) | 7/2$^−$ |
| $^{259}$Md | 101 | 158 | 259,10051(22) | 1,60(6) uur | ${\ce {{^{259}_{101}Md}->{^{255}_{99}Es}+\,_{2}^{4}\alpha }}$ (1,3%) | 7/2$^−$ |
| $^{260}$Md | 101 | 159 | 260,10365(34) | 27,8(8) dagen | SS (85%) | |
| $^{260}$Md | 101 | 159 | 260,10365(34) | 27,8(8) dagen | ${\ce {{^{260}_{101}Md}->{^{256}_{99}Es}+\,_{2}^{4}\alpha }}$ (5%) | |
| $^{260}$Md | 101 | 159 | 260,10365(34) | 27,8(8) dagen | ${\ce {{^{260}_{101}Md}+{e^{-}}->{^{260}_{100}Fm}+{\nu }_{e}}}$(5%) | |
| $^{260}$Md | 101 | 159 | 260,10365(34) | 27,8(8) dagen | ${\ce {{^{260}_{101}Md}->{^{260}_{102}No}+{e^{-}}+{\bar {\nu }}_{e}}}$ (3,5%) | |
| $^{261}$Md | 101 | 160 | 261,10572(70) | 40 min | | 7/2$^−$ |
| $^{262}$Md | 101 | 161 | 262,10887(63) | 3 min | | |

## 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
$^{245}$Md · $^{245m}$Md · $^{246}$Md · $^{247}$Md · $^{247m}$Md · $^{248}$Md · $^{249}$Md · $^{249m}$Md · $^{250}$Md · $^{251}$Md · $^{252}$Md · $^{253}$Md · $^{254}$Md · $^{254m}$Md · $^{255}$Md · $^{256}$Md · $^{257}$Md · $^{258}$Md · $^{258m}$Md · $^{259}$Md · $^{260}$Md · $^{261}$Md · $^{262}$Md