Isotopes of Mendelevium
List of known isotopes of the element Mendelevium.
| Isotope | t½ | % | Spin/parity | Radius | Isotopic mass | Discovery |
|---|---|---|---|---|---|---|
| 244Md | 0.38 ± s | syn. | — | — | 2.44·108 ±402 keV/c2 | 2020 |
| 245Md | 0.9 ±25 ms | syn. | (1/2-) | — | 2.45·108 ±279 keV/c2 | 1996 |
| 246Md | 0.9 ±2 s | syn. | — | — | 2.46·108 ±279 keV/c2 | 1996 |
| 247Md | 1.2 ±1 s | syn. | (7/2-) | — | 2.47·108 ±223 keV/c2 | 1981 |
| 248Md | 7 ±3 s | syn. | — | — | 2.48·108 ±198 keV/c2 | 1973 |
| 249Md | 21.7 ±20 s | syn. | (7/2-) | — | 2.49·108 ±176.5 keV/c2 | 1973 |
| 250Md | 52 ±6 s | syn. | — | — | 2.5·108 ±97.6 keV/c2 | 1973 |
| 251Md | 4 ±5 m | syn. | (7/2-) | — | 2.51·108 ±20.31 keV/c2 | 1973 |
| 252Md | 2.3 ±8 m | syn. | — | — | 2.52·108 ±98 keV/c2 | 1973 |
| 253Md | 6 ± m | syn. | (7/2-) | — | 2.53·108 ±34 keV/c2 | 1992 |
| 254Md | 10 ±3 m | syn. | — | — | 2.54·108 ±107 keV/c2 | 1970 |
| 255Md | 27 ±2 m | syn. | (7/2-) | — | 2.55·108 ±5.976 keV/c2 | 1958 |
| 256Md | 77.7 ±18 m | syn. | (1-) | — | 2.56·108 ±133 keV/c2 | 1955 |
| 257Md | 5.52 ±5 h | syn. | (7/2-) | — | 2.57·108 ±1.683 keV/c2 | 1965 |
| 258Md | 51.5 ±29 d | syn. | (8-) | — | 2.58·108 ±3.729 keV/c2 | 1970 |
| 259Md | 1.6 ±6 h | syn. | — | — | 2.591·108 ±108 keV/c2 | 1982 |
| 260Md | 31.8 ±5 d | syn. | — | — | 2.601·108 ±339 keV/c2 | 1989 |
244MdMendelevium-244
| Classification | z: 101; n: 143; m: 244 |
|---|---|
| Half life | 0.38 ± s |
| Natural abundance | synthetic nuclide |
| Decay modes | α decay; electron capture + β⁺ decay |
| Discovery | 2020 |
| Mass excess | 75,590 ±374 keV |
| Binding energy | 7,438 ±2 keV |
| Single-particle energy | 1,008 ±396 keV |
| Q value for electron capture | 6,633 ±424.5 keV |
245MdMendelevium-245
| Classification | z: 101; n: 144; m: 245 |
|---|---|
| Half life | 0.9 ±25 ms |
| Natural abundance | synthetic nuclide |
| Spin/parity | (1/2-) |
| Decay modes | α decay; spontaneous fission |
| Discovery | 1996 |
| Mass excess | 75,320 ±260 keV |
| Binding energy | 7,441 ±1 keV |
| Single-particle energy | 928 ±328 keV |
| Neutron separation energy | 8,344 ±456 keV |
| Q value for electron capture | 5,133 ±325 keV |
246MdMendelevium-246
| Classification | z: 101; n: 145; m: 246 |
|---|---|
| Half life | 0.9 ±2 s |
| Natural abundance | synthetic nuclide |
| Decay modes | α decay; spontaneous fission; electron capture (EC) |
| Discovery | 1996 |
| Mass excess | 76,110 ±260 keV |
| Binding energy | 7,441 ±1 keV |
| Single-particle energy | 1,365 ±325 keV |
| Neutron separation energy | 7,281 ±367 keV |
| Q value for electron capture | 5,923 ±260.3 keV |
247MdMendelevium-247
| Classification | z: 101; n: 146; m: 247 |
|---|---|
| Half life | 1.2 ±1 s |
| Natural abundance | synthetic nuclide |
| Spin/parity | (7/2-) |
| Decay modes | α decay; spontaneous fission |
| Discovery | 1981 |
| Mass excess | 75,930 ±207 keV |
| Binding energy | 7,444 ±1 keV |
| Single-particle energy | 1,544 ±208 keV |
| Neutron separation energy | 8,251 ±333 keV |
| Q value for electron capture | 4,264 ±274.9 keV |
248MdMendelevium-248
| Classification | z: 101; n: 147; m: 248 |
|---|---|
| Half life | 7 ±3 s |
| Natural abundance | synthetic nuclide |
| Decay modes | electron capture (EC); α decay |
| Discovery | 1973 |
| Mass excess | 76,940 ±184 keV |
| Binding energy | 7,442 ±1 keV |
| Single-particle energy | 2,014 ±258 keV |
| Neutron separation energy | 7,059 ±277 keV |
| Q value for electron capture | 5,050 ±184.1 keV |
| β⁻ decay energy | -3,741 ±290 keV |
249MdMendelevium-249
| Classification | z: 101; n: 148; m: 249 |
|---|---|
| Half life | 21.7 ±20 s |
| Natural abundance | synthetic nuclide |
| Spin/parity | (7/2-) |
| Decay modes | α decay; electron capture + β⁺ decay |
| Discovery | 1973 |
| Mass excess | 77,180 ±164.4 keV |
| Binding energy | 7,444 ±0.6603 keV |
| Single-particle energy | 2,005 ±164.6 keV |
| Neutron separation energy | 7,838 ±247 keV |
| Q value for electron capture | 3,661 ±164.5 keV |
| β⁻ decay energy | -4,606 ±324 keV |
| β⁻ decay energy with neutron | -11,580 ±278 keV |
250MdMendelevium-250
| Classification | z: 101; n: 149; m: 250 |
|---|---|
| Half life | 52 ±6 s |
| Natural abundance | synthetic nuclide |
| Decay modes | electron capture (EC); α decay |
| Discovery | 1973 |
| Mass excess | 78,390 ±90.92 keV |
| Binding energy | 7,441 ±0.3637 keV |
| Single-particle energy | 2,408 ±91.13 keV |
| Neutron separation energy | 6,853 ±187.8 keV |
| Q value for electron capture | 4,326 ±91.26 keV |
| β⁻ decay energy | -3,167 ±220 keV |
| β⁻ decay energy with neutron | -11,460 ±294 keV |
251MdMendelevium-251
| Classification | z: 101; n: 150; m: 251 |
|---|---|
| Half life | 4 ±5 m |
| Natural abundance | synthetic nuclide |
| Spin/parity | (7/2-) |
| Decay modes | electron capture + β⁺ decay; α decay |
| Discovery | 1973 |
| Mass excess | 78,960 ±18.91 keV |
| Binding energy | 7,441 ±0.0754 keV |
| Single-particle energy | 2,394 ±20.49 keV |
| Neutron separation energy | 7,503 ±92.86 keV |
| Q value for electron capture | 3,007 ±23.71 keV |
| β⁻ decay energy | -3,882 ±182 keV |
| β⁻ decay energy with neutron | -10,680 ±201 keV |
252MdMendelevium-252
| Classification | z: 101; n: 151; m: 252 |
|---|---|
| Half life | 2.3 ±8 m |
| Natural abundance | synthetic nuclide |
| Decay modes | electron capture (EC) |
| Discovery | 1973 |
| Mass excess | 80,460 ±91.28 keV |
| Binding energy | 7,438 ±0.3622 keV |
| Single-particle energy | 2,780 ±92.39 keV |
| Neutron separation energy | 6,570 ±93.22 keV |
| Q value for electron capture | 3,650 ±91.43 keV |
| β⁻ decay energy | -2,405 ±91.75 keV |
| β⁻ decay energy with neutron | -10,460 ±203 keV |
253MdMendelevium-253
| Classification | z: 101; n: 152; m: 253 |
|---|---|
| Half life | 6 ± m |
| Natural abundance | synthetic nuclide |
| Spin/parity | (7/2-) |
| Decay modes | electron capture + β⁺ decay; α decay |
| Discovery | 1992 |
| Mass excess | 81,170 ±31 keV |
| Binding energy | 7,438 keV |
| Single-particle energy | 2,933 ±32 keV |
| Neutron separation energy | 7,366 ±96 keV |
| Q value for electron capture | 1,827 ±31.03 keV |
| β⁻ decay energy | -3,186 ±32 keV |
| β⁻ decay energy with neutron | -9,770 ±33 keV |
254MdMendelevium-254
| Classification | z: 101; n: 153; m: 254 |
|---|---|
| Half life | 10 ±3 m |
| Natural abundance | synthetic nuclide |
| Decay modes | electron capture + β⁺ decay |
| Discovery | 1970 |
| Mass excess | 83,450 ±100 keV |
| Binding energy | 7,432 keV |
| Single-particle energy | 3,182 ±100 keV |
| Neutron separation energy | 5,792 ±105 keV |
| Q value for electron capture | 2,550 ±100 keV |
| β⁻ decay energy | -1,271 ±100 keV |
| β⁻ decay energy with neutron | -8,977 ±100 keV |
255MdMendelevium-255
| Classification | z: 101; n: 154; m: 255 |
|---|---|
| Half life | 27 ±2 m |
| Natural abundance | synthetic nuclide |
| Spin/parity | (7/2-) |
| Decay modes | electron capture (EC); α decay |
| Discovery | 1958 |
| Mass excess | 84,840 ±5.567 keV |
| Binding energy | 7,428 ±0.0218 keV |
| Single-particle energy | 3,349 ±5.728 keV |
| Neutron separation energy | 6,682 ±100 keV |
| Q value for electron capture | 1,041 ±6.817 keV |
| β⁻ decay energy | -1,970 ±15.1 keV |
| β⁻ decay energy with neutron | -7,953 ±11.1 keV |
256MdMendelevium-256
| Classification | z: 101; n: 155; m: 256 |
|---|---|
| Half life | 77.7 ±18 m |
| Natural abundance | synthetic nuclide |
| Spin/parity | (1-) |
| Decay modes | electron capture (EC); α decay; spontaneous fission |
| Discovery | 1955 |
| Mass excess | 87,450 ±124 keV |
| Binding energy | 7,421 keV |
| Single-particle energy | 3,633 ±124 keV |
| Neutron separation energy | 5,457 ±124 keV |
| Q value for electron capture | 1,971 ±124 keV |
| β⁻ decay energy | -367 ±124 keV |
| β⁻ decay energy with neutron | -7,427 ±124 keV |
257MdMendelevium-257
| Classification | z: 101; n: 156; m: 257 |
|---|---|
| Half life | 5.52 ±5 h |
| Natural abundance | synthetic nuclide |
| Spin/parity | (7/2-) |
| Decay modes | electron capture (EC); α decay; spontaneous fission |
| Discovery | 1965 |
| Mass excess | 88,990 ±1.569 keV |
| Binding energy | 7,417 ±0.0061 keV |
| Single-particle energy | 3,781 ±3.335 keV |
| Neutron separation energy | 6,535 ±124 keV |
| Q value for electron capture | 402.3 ±4.624 keV |
| β⁻ decay energy | -1,255 ±6.169 keV |
| β⁻ decay energy with neutron | -6,902 ±7.568 keV |
258MdMendelevium-258
| Classification | z: 101; n: 157; m: 258 |
|---|---|
| Half life | 51.5 ±29 d |
| Natural abundance | synthetic nuclide |
| Spin/parity | (8-) |
| Decay modes | α decay |
| Discovery | 1970 |
| Mass excess | 91,690 ±3.474 keV |
| Binding energy | 7,409 ±0.0135 keV |
| Single-particle energy | 4,188 ±5.502 keV |
| Neutron separation energy | 5,373 ±3.535 keV |
| Q value for electron capture | 1,264 ±200 keV |
| β⁻ decay energy | 213 ±100 keV |
| β⁻ decay energy with neutron | -6,629 ±6.959 keV |
259MdMendelevium-259
| Classification | z: 101; n: 158; m: 259 |
|---|---|
| Half life | 1.6 ±6 h |
| Natural abundance | synthetic nuclide |
| Decay modes | spontaneous fission; α decay |
| Discovery | 1982 |
| Mass excess | 93,560 ±101 keV |
| Binding energy | 7,405 keV |
| Single-particle energy | 4,151 ±224 keV |
| Neutron separation energy | 6,198 ±101 keV |
| Q value for electron capture | -140 ±300.4 keV |
| β⁻ decay energy | -515 ±101 keV |
| β⁻ decay energy with neutron | -5,985 ±142 keV |
260MdMendelevium-260
| Classification | z: 101; n: 159; m: 260 |
|---|---|
| Half life | 31.8 ±5 d |
| Natural abundance | synthetic nuclide |
| Decay modes | spontaneous fission; α decay; electron capture (EC) |
| Discovery | 1989 |
| Mass excess | 96,550 ±316 keV |
| Binding energy | 7,396 ±1 keV |
| Single-particle energy | 4,443 ±424 keV |
| Neutron separation energy | 5,086 ±332 keV |
| β⁻ decay energy | 940 ±374 keV |
| β⁻ decay energy with neutron | -5,601 ±316 keV |