Pa
Protactinium
Z 91 231.036 g/molActinide Radioactive
| 231Pa | 140 | 231.0359 | 33,424.3 | 100.0% | 32.65 ky | 3/2- | α→227Ac(~100%) CD→207Tl(1.34e-9%) SF(<3e-10%) CD→208Pb(9.9e-13%) | 1918 |
| 211Pa | 120 | 211.0237 | 22,050.0 | --- | 6.0 ms | 9/2- | α→207Ac(100%) β⁺→211Th p→210Th | 2006 |
| 212Pa | 121 | 212.0232 | 21,600.0 | --- | 5.8 ms | (3+) | α→208Ac(100%) | 1997 |
| 213Pa | 122 | 213.0211 | 19,650.0 | --- | 7.4 ms | 9/2- | α→209Ac(100%) | 1995 |
| 214Pa | 123 | 214.0209 | 19,460.0 | --- | 17.0 ms | (7+) | α→210Ac(100%) | 1995 |
| 215Pa | 124 | 215.0191 | 17,800.0 | --- | 14.0 ms | 9/2- | α→211Ac(100%) | 1979 |
| 216Pa | 125 | 216.0191 | 17,824.0 | --- | 105.0 ms | (5+) | α→212Ac(100%) β⁺→216Th | 1972 |
| 217Pa | 126 | 217.0183 | 17,055.0 | --- | 3.8 ms | 9/2- | α→213Ac(100%) β⁻→217U | 1968 |
| 217mPa | 126 | 217.0203 | 18,915.0 | --- | 1.08 ms | (23/2-) | α→213Ac(73%) γ→217Pa | 1979 |
| 218Pa | 127 | 218.02 | 18,650.0 | --- | 108.0 µs | (8-) | α→214Ac(100%) | 1979 |
| 218mPa | 127 | 218.0201 | 18,731.0 | --- | 150.0 µs | (1-) | α→214Ac(100%) | 1979 |
| 219Pa | 128 | 219.0199 | 18,580.0 | --- | 56.0 ns | 9/2- | α→215Ac(100%) β⁺→219Th | 2005 |
| 220Pa | 129 | 220.0218 | 20,278.0 | --- | 850.0 ns | (1-) | α→216Ac(100%) β⁺→220Th | 2005 |
| 220mPa | 129 | 220.0218 | 20,304.0 | --- | 410.0 ns | --- | α→216Ac(100%) | 2018 |
| 220nPa | 129 | 220.0221 | 20,570.0 | --- | 260.0 ns | --- | α→216Ac(100%) | 2018 |
| 221Pa | 130 | 221.0219 | 20,370.0 | --- | 5.9 µs | 9/2- | α→217Ac(100%) | 1983 |
| 222Pa | 131 | 222.0237 | 22,060.0 | --- | 3.8 ms | (1-) | α→218Ac(100%) | 1970 |
| 223Pa | 132 | 223.024 | 22,340.0 | --- | 5.3 ms | 9/2- | α→219Ac(100%) β⁺→223Th | 1970 |
| 224Pa | 133 | 224.0256 | 23,862.0 | --- | 844.0 ms | (5-) | α→220Ac(100%) β⁺→224Th | 1958 |
| 225Pa | 134 | 225.0262 | 24,360.0 | --- | 1.71 s | (5/2-) | α→221Ac(100%) | 1958 |
| 226Pa | 135 | 226.0279 | 26,034.0 | --- | 1.8 m | (1-) | α→222Ac(74%) β⁺→226Th(26%) | 1949 |
| 227Pa | 136 | 227.0288 | 26,830.0 | --- | 38.3 m | (5/2-) | α→223Ac(85%) EC→227Th(15%) | 1948 |
| 228Pa | 137 | 228.0311 | 28,924.0 | --- | 22.0 h | 3+ | β⁺→228Th(98.15%) α→224Ac(1.85%) | 1948 |
| 229Pa | 138 | 229.0321 | 29,897.0 | --- | 1.55 d | 5/2+ | EC→229Th(99.51%) α→225Ac(0.49%) | 1949 |
| 229mPa | 138 | 229.0321 | 29,909.0 | --- | 420.0 ns | 3/2- | γ→229Pa(100%) | 1982 |
| 230Pa | 139 | 230.0345 | 32,174.0 | --- | 17.4 d | 2- | β⁺→230Th(92.2%) β⁻→230U(7.8%) α→226Ac(0.003%) | 1948 |
| 232Pa | 141 | 232.0386 | 35,947.0 | --- | 1.32 d | (2-) | β⁻→232U(100%) EC→232Th | 1949 |
| 233Pa | 142 | 233.0402 | 37,489.4 | --- | 26.98 d | 3/2- | β⁻→233U(100%) | 1938 |
| 234Pa | 143 | 234.0433 | 40,339.0 | --- | 6.7 h | 4+ | β⁻→234U(100%) | 1913 |
| 234mPa | 143 | 234.0434 | 40,417.9 | --- | 1.16 m | (0-) | β⁻→234U(~100%) γ→234Pa(0.16%) | 1951 |
| 235Pa | 144 | 235.0454 | 42,289.0 | --- | 24.4 m | 3/2- | β⁻→235U(100%) | 1950 |
| 236Pa | 145 | 236.0487 | 45,334.0 | --- | 9.1 m | (1-) | β⁻→236U(~100%) β⁻SF(6e-8%) | 1963 |
| 237Pa | 146 | 237.051 | 47,528.0 | --- | 8.7 m | 1/2+ | β⁻→237U(100%) | 1954 |
| 238Pa | 147 | 238.0546 | 50,894.0 | --- | 2.28 m | (3-) | β⁻→238U(~100%) β⁻SF(<2.6e-6%) | 1968 |
| 239Pa | 148 | 239.0573 | 53,340.0 | --- | 1.8 h | (1/2+) | β⁻→239U(100%) | 1995 |
| 240Pa | 149 | 240.0612 | 57,010.0 | --- | 20.0 s | (3+) | β⁻→240U | --- |
| 241Pa | 150 | 241.0641 | 59,740.0 | --- | 28.0 m | (1/2+) | β⁻→241U | --- |