| 释义 |
- List of isotopes Notes
- References
{{infobox francium isotopes}}Francium (87Fr) has no stable isotopes. A standard atomic weight cannot be given. Its most stable isotope is 223Fr with a half-life of 22 minutes, occurring in trace quantities as an intermediate decay product of 235U. Of elements whose most stable isotopes have been identified with certainty, francium is the most unstable. All elements with atomic number of greater than or equal to 106 (seaborgium) have most-stable-known isotopes shorter than that of francium, but those elements have only a relatively small number of isotopes discovered, thus, there is the possibility of a yet-unknown isotope having a longer half-life. List of isotopes nuclide
symbol | historic
name | Z(p) | N(n) |
isotopic mass (u)
| half-life | decay
mode(s)[1][2] | daughter
isotope(s) | nuclear
spin and
parity | representative
isotopic
composition
(mole fraction) | range of natural
variation
(mole fraction) | | excitation energy |
|---|
| 199Fr | 87 | 112 | 199.00726(4) | 16(7) ms | 1/2+# | | 200Fr | 87 | 113 | 200.00657(8) | 24(10) ms | α | 196At | 3+# | | 200mFr | | 60(110) keV | 650(210) ms | α | 196At | 10−# | | | | IT (rare) | 200Fr | | 201Fr | | 87 | 114 | 201.00386(8) | 67(3) ms | α (99%) | 197At | (9/2−) | | | | β+ (1%) | 201Rn | | 202Fr | | 87 | 115 | 202.00337(5) | 290(30) ms | α (97%) | 198At | (3+) | | | | β+ (3%) | 202Rn | | 202mFr | | 330(90)# keV | 340(40) ms | α (97%) | 198At | (10−) | | | | β+ (3%) | 202Rn | | 203Fr | | 87 | 116 | 203.000925(17) | 0.55(2) s | α (95%) | 199At | (9/2−)# | | | | β+ (5%) | 203Rn | | 204Fr | | 87 | 117 | 204.000653(26) | 1.7(3) s | α (96%) | 200At | (3+) | | | | β+ (4%) | 204Rn | | 204m1Fr | | 50(4) keV | 2.6(3) s | α (90%) | 200At | (7+) | | | | β+ (10%) | 204Rn | | 204m2Fr | 326(4) keV | 1.7(6) s | (10−) | | 205Fr | | 87 | 118 | 204.998594(8) | 3.80(3) s | α (99%) | 201At | (9/2−) | | | | β+ (1%) | 205Rn | | 206Fr | | 87 | 119 | 205.99867(3) | ~16 s | β+ (58%) | 206Rn | (2+,3+) | | | | α (42%) | 202At | | 206m1Fr | 190(40) keV | 15.9(1) s | (7+) | | 206m2Fr | 730(40) keV | 700(100) ms | (10−) | | 207Fr | | 87 | 120 | 206.99695(5) | 14.8(1) s | α (95%) | 203At | 9/2− | | | | β+ (5%) | 207Rn | | 208Fr | | 87 | 121 | 207.99714(5) | 59.1(3) s | α (90%) | 204At | 7+ | | | | β+ (10%) | 208Rn | | 209Fr | | 87 | 122 | 208.995954(16) | 50.0(3) s | α (89%) | 205At | 9/2− | | | | β+ (11%) | 209Rn | | 210Fr | | 87 | 123 | 209.996408(24) | 3.18(6) min | α (60%) | 206At | 6+ | | | | β+ (40%) | 210Rn | | 211Fr | | 87 | 124 | 210.995537(23) | 3.10(2) min | α (80%) | 207At | 9/2− | | | | β+ (20%) | 211Rn | | 212Fr | | 87 | 125 | 211.996202(28) | 20.0(6) min | β+ (57%) | 212Rn | 5+ | | | | α (43%) | 208At | | 213Fr | | 87 | 126 | 212.996189(8) | 34.6(3) s | α (99.45%) | 209At | 9/2− | | | | β+ (.55%) | 213Rn | | 214Fr | 87 | 127 | 213.998971(9) | 5.0(2) ms | α | 210At | (1−) | | 214m1Fr | 123(6) keV | 3.35(5) ms | α | 210At | (8−) | | 214m2Fr | 638(6) keV | 103(4) ns | (11+) | | 214m3Fr | 6477+Y keV | 108(7) ns | (33+) | | 215Fr | 87 | 128 | 215.000341(8) | 86(5) ns | α | 211At | 9/2− | | 216Fr | | 87 | 129 | 216.003198(15) | 0.70(2) µs | α | 212At | (1−) | | | | β+ (2×10−7%) | 216Rn | | 217Fr | 87 | 130 | 217.004632(7) | 16.8(19) µs | α | 213At | 9/2− | | 218Fr | 87 | 131 | 218.007578(5) | 1.0(6) ms | α | 214At | 1− | | 218m1Fr | | 86(4) keV | 22.0(5) ms | α | 214At | | | | | IT (rare) | 218Fr | | 218m2Fr | 200(150)# keV | high | | 219Fr | 87 | 132 | 219.009252(8) | 20(2) ms | α | 215At | 9/2− | | 220Fr | | 87 | 133 | 220.012327(4) | 27.4(3) s | α (99.65%) | 216At | 1+ | | | | β− (.35%) | 220Ra | | 221Fr | | 87 | 134 | 221.014255(5) | 4.9(2) min | α (99.9%) | 217At | 5/2− | | | | β− (.1%) | 221Ra | | CD (8.79×10−11%) | 207Tl
14C | | 222Fr | 87 | 135 | 222.017552(23) | 14.2(3) min | β− | 222Ra | 2− | | 223Fr | Actinium K | 87 | 136 | 223.0197359(26) | 22.00(7) min | β− (99.99%) | 223Ra | 3/2(−) | Trace[3] | | | α (.006%) | 219At | | 224Fr | 87 | 137 | 224.02325(5) | 3.33(10) min | β− | 224Ra | 1− | | 225Fr | 87 | 138 | 225.02557(3) | 4.0(2) min | β− | 225Ra | 3/2− | | 226Fr | 87 | 139 | 226.02939(11) | 49(1) s | β− | 226Ra | 1− | | 227Fr | 87 | 140 | 227.03184(11) | 2.47(3) min | β− | 227Ra | 1/2+ | | 228Fr | 87 | 141 | 228.03573(22)# | 38(1) s | β− | 228Ra | 2− | | 229Fr | 87 | 142 | 229.03845(4) | 50.2(4) s | β− | 229Ra | (1/2+)# | | 230Fr | 87 | 143 | 230.04251(48)# | 19.1(5) s | β− | 230Ra | | 231Fr | 87 | 144 | 231.04544(50)# | 17.6(6) s | β− | 231Ra | (1/2+)# | | 232Fr | 87 | 145 | 232.04977(69)# | 5(1) s | β− | 232Ra |
1. ^{{cite web |url=http://www.nucleonica.net/unc.aspx |title=Universal Nuclide Chart |publisher=nucleonica |registration=yes}}
2. ^Abbreviations:
CD: Cluster decay
IT: Isomeric transition
3. ^Intermediate decay product of 235U
Notes - Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
- Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.
References - Isotope masses from:
- Isotopic compositions and standard atomic masses from:
- {{CAWIA 2003}}
- {{CIAAW 2005}}
- Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- {{NUBASE 2003}}
- {{NNDC}}
- {{CRC85|chapter=11}}
{{Navbox element isotopes}} 2 : Isotopes of francium|Lists of isotopes by element |