Ac
Actinium
Z 89 227.0 g/molActinide Radioactive
| 205Ac | 116 | 205.0151 | 14,110.0 | --- | 80.0 ms | 9/2- | α→201Fr(100%) β⁺→205Ra | 2014 |
| 206Ac | 117 | 206.0145 | 13,480.0 | --- | 25.0 ms | 3+ | α→202Fr(100%) β⁺→206Ra | 1998 |
| 206mAc | 117 | 206.0147 | 13,690.0 | --- | 41.0 ms | 10- | α→202Fr(100%) β⁺→206Ra | 1996 |
| 207Ac | 118 | 207.012 | 11,150.0 | --- | 31.0 ms | 9/2- | α→203Fr(100%) | 1994 |
| 208Ac | 119 | 208.0116 | 10,760.0 | --- | 97.0 ms | 3+ | α→204Fr(100%) β⁺→208Ra | 1994 |
| 208mAc | 119 | 208.0121 | 11,258.0 | --- | 28.0 ms | 10- | α→204Fr(100%) γ→208Ac β⁺→208Ra | 1994 |
| 209Ac | 120 | 209.0095 | 8,840.0 | --- | 94.0 ms | 9/2- | α→205Fr(100%) β⁺→209Ra | 1968 |
| 210Ac | 121 | 210.0094 | 8,760.0 | --- | 350.0 ms | (7+) | α→206Fr(100%) β⁺→210Ra | 1968 |
| 211Ac | 122 | 211.0077 | 7,140.0 | --- | 213.0 ms | 9/2- | α→207Fr(100%) β⁺→211Ra | 1968 |
| 212Ac | 123 | 212.0078 | 7,300.0 | --- | 895.0 ms | 7+ | α→208Fr(100%) β⁺→212Ra | 1968 |
| 213Ac | 124 | 213.0066 | 6,141.0 | --- | 738.0 ms | 9/2- | α→209Fr(100%) β⁺→213Ra | 1968 |
| 214Ac | 125 | 214.0069 | 6,433.0 | --- | 8.2 s | 5+ | α→210Fr(93%) β⁺→214Ra(7%) | 1968 |
| 215Ac | 126 | 215.0065 | 6,031.0 | --- | 171.0 ms | 9/2- | α→211Fr(~100%) β⁺→215Ra(0.09%) | 1968 |
| 215mAc | 126 | 215.0084 | 7,827.0 | --- | 185.0 ns | (21/2-) | γ→215Ac(100%) | 1983 |
| 215nAc | 126 | 215.0091 | 8,520.0 | --- | 335.0 ns | (29/2+) | γ→215Ac(100%) | 1983 |
| 216Ac | 127 | 216.0087 | 8,150.0 | --- | 440.0 µs | (1-) | α→212Fr(100%) β⁺→216Ra | 1967 |
| 216mAc | 127 | 216.0088 | 8,188.0 | --- | 441.0 µs | (9-) | α→212Fr(100%) β⁺→216Ra | 1966 |
| 216nAc | 127 | 216.0092 | 8,570.0 | --- | --- | --- | γ→216Ac(100%) | 2006 |
| 217Ac | 128 | 217.0093 | 8,702.0 | --- | 69.0 ns | 9/2- | α→213Fr(100%) β⁺→217Ra | 1972 |
| 217mAc | 128 | 217.0115 | 10,715.0 | --- | 740.0 ns | 29/2+ | γ→217Ac(95.49%) α→213Fr(4.51%) | 1973 |
| 218Ac | 129 | 218.0116 | 10,850.0 | --- | 1.0 µs | (1-) | α→214Fr(100%) | 1970 |
| 218mAc | 129 | 218.0117 | 10,900.0 | --- | --- | (8-) | γ→218Ac α→214Fr β⁺→218Ra | --- |
| 218nAc | 129 | 218.0123 | 11,460.0 | --- | 103.0 ns | (11+) | γ→218Ac(100%) | 1994 |
| 219Ac | 130 | 219.0124 | 11,570.0 | --- | 9.4 µs | 9/2- | α→215Fr(100%) β⁺→219Ra | 1970 |
| 220Ac | 131 | 220.0148 | 13,744.0 | --- | 26.36 ms | (3-) | α→216Fr(100%) β⁺→220Ra | 1970 |
| 221Ac | 132 | 221.0156 | 14,530.0 | --- | 52.0 ms | (9/2-) | α→217Fr(100%) | 1968 |
| 222Ac | 133 | 222.0178 | 16,622.0 | --- | 5.0 s | 1- | α→218Fr(99%) β⁺→222Ra(1%) | 1949 |
| 222mAc | 133 | 222.0179 | 16,700.0 | --- | 1.05 m | (5+) | α→218Fr(98.6%) β⁺→222Ra(1.4%) γ→222Ac | 1972 |
| 223Ac | 134 | 223.0191 | 17,825.0 | --- | 2.1 m | (5/2-) | α→219Fr(99%) EC→223Ra | 1948 |
| 224Ac | 135 | 224.0217 | 20,234.0 | --- | 2.78 h | (0-) | β⁺→224Ra(90.5%) α→220Fr(9.5%) β⁻→224Th | 1948 |
| 225Ac | 136 | 225.0232 | 21,637.0 | --- | 9.92 d | 3/2- | α→221Fr(~100%) CD→211Bi(5.3e-10%) | 1947 |
| 226Ac | 137 | 226.0261 | 24,309.0 | --- | 1.22 d | (1-) | β⁻→226Th(83%) EC→226Ra(17%) α→222Fr(0.006%) | 1950 |
| 227Ac | 138 | 227.0278 | 25,849.5 | --- | 21.77 y | 3/2- | β⁻→227Th(98.62%) α→223Fr(1.38%) | 1851 |
| 228Ac | 139 | 228.031 | 28,894.7 | --- | 6.15 h | 3+ | β⁻→228Th(100%) | 1908 |
| 228mAc | 139 | 228.0316 | 29,430.0 | --- | 3.0 m | --- | γ→228Ac β⁻→228Th | 2008 |
| 229Ac | 140 | 229.0329 | 30,690.0 | --- | 1.05 h | 3/2+ | β⁻→229Th(100%) | 1952 |
| 230Ac | 141 | 230.0363 | 33,838.0 | --- | 2.03 m | (1+) | β⁻→230Th(~100%) β⁻SF(1.2e-6%) | 1973 |
| 231Ac | 142 | 231.0384 | 35,763.0 | --- | 7.5 m | 1/2+ | β⁻→231Th(100%) | 1973 |
| 232Ac | 143 | 232.042 | 39,154.0 | --- | 1.98 m | (1+) | β⁻→232Th(100%) | 1986 |
| 233Ac | 144 | 233.0443 | 41,308.0 | --- | 2.38 m | (1/2+) | β⁻→233Th(100%) | 1983 |
| 234Ac | 145 | 234.0481 | 44,841.0 | --- | 45.0 s | (1+) | β⁻→234Th(100%) | 1986 |
| 234mAc | 145 | 234.0483 | 44,980.0 | --- | --- | --- | β⁻→234Th γ→234Ac | 2008 |
| 234nAc | 145 | 234.0488 | 45,460.0 | --- | 3.0 m | --- | β⁻→234Th γ→234Ac | 2008 |
| 235Ac | 146 | 235.0508 | 47,357.0 | --- | 1.03 m | (1/2+) | β⁻→235Th(100%) | 2006 |
| 236Ac | 147 | 236.055 | 51,220.0 | --- | 4.5 m | (3+) | β⁻→236Th(100%) | 2010 |
| 237Ac | 148 | 237.058 | 54,020.0 | --- | 23.0 s | (1/2+) | β⁻→237Th | --- |