Md
Mendelevium
Z 101 258.0 g/molActinide Radioactive
| 244Md | 143 | 244.0812 | 75,600.0 | --- | 360.0 ms | (3+) | α→240Es(100%) β⁺SF(<14%) β⁺→244Fm | 2020 |
| 244mMd | 143 | 244.0814 | 75,800.0 | --- | --- | (7+) | γ→244Md β⁺→244Fm | 2020 |
| 245Md | 144 | 245.0809 | 75,330.0 | --- | 380.0 ms | (7/2-) | α→241Es(100%) β⁺→245Fm | 1996 |
| 245mMd | 144 | 245.081 | 75,430.0 | --- | 900.0 µs | (1/2-) | SF(100%) α→241Es | 1996 |
| 246Md | 145 | 246.0817 | 76,120.0 | --- | 920.0 ms | (1-) | α→242Es(100%) | 1996 |
| 246mMd | 145 | 246.0818 | 76,170.0 | --- | 4.4 s | (4-) | β⁺→246Fm(>77%) α→242Es(57%) α→242Es(<23%) β⁺SF(>10%) | 2010 |
| 247Md | 146 | 247.0815 | 75,940.0 | --- | 1.19 s | (7/2-) | α→243Es(~100%) SF(<0.1%) | 1981 |
| 247mMd | 146 | 247.0818 | 76,200.0 | --- | 250.0 ms | (1/2-) | α→243Es(79%) SF(21%) | 1993 |
| 248Md | 147 | 248.0826 | 76,950.0 | --- | 7.0 s | --- | β⁺→248Fm(80%) α→244Es(20%) β⁺SF(<0.05%) | 1973 |
| 249Md | 148 | 249.0829 | 77,180.0 | --- | 25.6 s | (7/2-) | α→245Es(75%) β⁺→249Fm | 1973 |
| 249mMd | 148 | 249.083 | 77,280.0 | --- | 1.9 s | (1/2-) | α→245Es(100%) | 2001 |
| 250Md | 149 | 250.0842 | 78,400.0 | --- | 54.0 s | (2-) | β⁺→250Fm(92.974%) α→246Es(7%) β⁺SF(0.026%) | 1973 |
| 250mMd | 149 | 250.0843 | 78,520.0 | --- | 42.4 s | (7+) | α→246Es β⁺→250Fm γ→250Md | 2019 |
| 251Md | 150 | 251.0848 | 78,967.0 | --- | 4.21 m | (7/2-) | α→247Es(10%) β⁺→251Fm | 1973 |
| 252Md | 151 | 252.0864 | 80,470.0 | --- | 2.3 m | (1+) | β⁺→252Fm(100%) α→248Es | 1973 |
| 253Md | 152 | 253.0871 | 81,170.0 | --- | 12.0 m | (7/2-) | β⁺→253Fm(~100%) α→249Es(0.7%) | 1992 |
| 254Md | 153 | 254.0896 | 83,450.0 | --- | 10.0 m | (0-) | β⁺→254Fm(100%) α→250Es | 1970 |
| 254mMd | 153 | 254.0896 | 83,500.0 | --- | 28.0 m | (3-) | β⁺→254Fm(100%) α→250Es | 1970 |
| 255Md | 154 | 255.0911 | 84,842.0 | --- | 27.0 m | 7/2- | β⁺→255Fm(93%) α→251Es(7%) SF | 1958 |
| 256Md | 155 | 256.0939 | 87,460.0 | --- | 1.3 h | (1-) | β⁺→256Fm(90.8%) α→252Es(9.2%) SF(<3%) | 1955 |
| 256mMd | 155 | 256.0941 | 87,620.0 | --- | 1.67 h | (7-) | β⁺→256Fm α→252Es SF | --- |
| 257Md | 156 | 257.0955 | 88,992.5 | --- | 5.52 h | (7/2-) | EC→257Fm(85%) α→253Es(15%) SF | 1965 |
| 258Md | 157 | 258.0984 | 91,690.0 | --- | 51.59 d | (8-) | α→254Es(~100%) β⁺→258Fm(<0.002%) β⁻→258No(<0.002%) | 1970 |
| 258mMd | 157 | 258.0984 | 91,690.0 | --- | 57.0 m | (1-) | EC→258Fm(85%) SF(<15%) α→254Es(<1.2%) β⁻→258No | 1980 |
| 259Md | 158 | 259.1004 | 93,560.0 | --- | 1.6 h | (7/2-) | SF(100%) α→255Es | 1982 |
| 260Md | 159 | 260.1037 | 96,550.0 | --- | 27.8 d | --- | SF(100%) α→256Es(<5%) EC→260Fm(<5%) β⁻→260No(<3.5%) | 1989 |
| 261Md | 160 | 261.1058 | 98,580.0 | --- | 40.0 m | (7/2-) | α→257Es | --- |
| 262Md | 161 | 262.1091 | 101,670.0 | --- | 3.0 m | --- | SF α→258Es | --- |