ไอโซโทปของเรเดียม
รายชื่อไอโซโทป

| สัญลักษณ์ นิวไคลด์ | ชื่อ ดั้งเดิม | Z(p)> พลังงานกระตุ้น | N(n)> พลังงานกระตุ้น |   มวลของไอโซโทป (u)  > พลังงานกระตุ้น | ครึ่งชีวิต | รูปแบบ การสลายตัว(s) | ไอโซโทป ลูกสาว(s) | nuclear spin | representative isotopic composition (mole fraction) | range of natural variation (mole fraction) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 202Ra |  | 88 | 114 | 202.00989(7) | 2.6(21) ms [0.7(+33−3) ms] |  |  | 0+ |  |  |
| 203Ra |  | 88 | 115 | 203.00927(9) | 4(3) ms | α | 199Rn | (3/2−) |  |  |
| 203Ra |  | 88 | 115 | 203.00927(9) | 4(3) ms | β+ (rare) | 203Fr | (3/2−) |  |  |
| 203mRa |  | 220(90) keV | 220(90) keV | 220(90) keV | 41(17) ms | α | 199Rn | (13/2+) |  |  |
| 203mRa |  | 220(90) keV | 220(90) keV | 220(90) keV | 41(17) ms | β+ (rare) | 203Fr | (13/2+) |  |  |
| 204Ra |  | 88 | 116 | 204.006500(17) | 60(11) ms [59(+12−9) ms] | α (99.7%) | 200Rn | 0+ |  |  |
| 204Ra |  | 88 | 116 | 204.006500(17) | 60(11) ms [59(+12−9) ms] | β+ (.3%) | 204Fr | 0+ |  |  |
| 205Ra |  | 88 | 117 | 205.00627(9) | 220(40) ms [210(+60−40) ms] | α | 201Rn | (3/2−) |  |  |
| 205Ra |  | 88 | 117 | 205.00627(9) | 220(40) ms [210(+60−40) ms] | β+ (rare) | 205Fr | (3/2−) |  |  |
| 205mRa |  | 310(110)# keV | 310(110)# keV | 310(110)# keV | 180(50) ms [170(+60−40) ms] | α | 201Rn | (13/2+) |  |  |
| 205mRa |  | 310(110)# keV | 310(110)# keV | 310(110)# keV | 180(50) ms [170(+60−40) ms] | IT (rare) | 205Ra | (13/2+) |  |  |
| 206Ra |  | 88 | 118 | 206.003827(19) | 0.24(2) s | α | 202Rn | 0+ |  |  |
| 207Ra |  | 88 | 119 | 207.00380(6) | 1.3(2) s | α (90%) | 203Rn | (5/2−,3/2−) |  |  |
| 207Ra |  | 88 | 119 | 207.00380(6) | 1.3(2) s | β+ (10%) | 207Fr | (5/2−,3/2−) |  |  |
| 207mRa |  | 560(50) keV | 560(50) keV | 560(50) keV | 57(8) ms | IT (85%) | 207Ra | (13/2+) |  |  |
| 207mRa |  | 560(50) keV | 560(50) keV | 560(50) keV | 57(8) ms | α (15%) | 203Rn | (13/2+) |  |  |
| 207mRa |  | 560(50) keV | 560(50) keV | 560(50) keV | 57(8) ms | β+ (.55%) | 207Fr | (13/2+) |  |  |
| 208Ra |  | 88 | 120 | 208.001840(17) | 1.3(2) s | α (95%) | 204Rn | 0+ |  |  |
| 208Ra |  | 88 | 120 | 208.001840(17) | 1.3(2) s | β+ (5%) | 208Fr | 0+ |  |  |
| 208mRa |  | 1800(200) keV | 1800(200) keV | 1800(200) keV | 270 ns |  |  | (8+) |  |  |
| 209Ra |  | 88 | 121 | 209.00199(5) | 4.6(2) s | α (90%) | 205Rn | 5/2− |  |  |
| 209Ra |  | 88 | 121 | 209.00199(5) | 4.6(2) s | β+ (10%) | 209Fr | 5/2− |  |  |
| 210Ra |  | 88 | 122 | 210.000495(16) | 3.7(2) s | α (96%) | 206Rn | 0+ |  |  |
| 210Ra |  | 88 | 122 | 210.000495(16) | 3.7(2) s | β+ (4%) | 210Fr | 0+ |  |  |
| 210mRa |  | 1800(200) keV | 1800(200) keV | 1800(200) keV | 2.24 µs |  |  | (8+) |  |  |
| 211Ra |  | 88 | 123 | 211.000898(28) | 13(2) s | α (97%) | 207Rn | 5/2(−) |  |  |
| 211Ra |  | 88 | 123 | 211.000898(28) | 13(2) s | β+ (3%) | 211Fr | 5/2(−) |  |  |
| 212Ra |  | 88 | 124 | 211.999794(12) | 13.0(2) s | α (85%) | 208Rn | 0+ |  |  |
| 212Ra |  | 88 | 124 | 211.999794(12) | 13.0(2) s | β+ (15%) | 212Fr | 0+ |  |  |
| 212m1Ra |  | 1958.4(5) keV | 1958.4(5) keV | 1958.4(5) keV | 10.9(4) µs |  |  | (8)+ |  |  |
| 212m2Ra |  | 2613.4(5) keV | 2613.4(5) keV | 2613.4(5) keV | 0.85(13) µs |  |  | (11)− |  |  |
| 213Ra |  | 88 | 125 | 213.000384(22) | 2.74(6) min | α (80%) | 209Rn | 1/2− |  |  |
| 213Ra |  | 88 | 125 | 213.000384(22) | 2.74(6) min | β+ (20%) | 213Fr | 1/2− |  |  |
| 213mRa |  | 1769(6) keV | 1769(6) keV | 1769(6) keV | 2.1(1) ms | IT (99%) | 213Ra | 17/2−# |  |  |
| 213mRa |  | 1769(6) keV | 1769(6) keV | 1769(6) keV | 2.1(1) ms | α (1%) | 209Rn | 17/2−# |  |  |
| 214Ra |  | 88 | 126 | 214.000108(10) | 2.46(3) s | α (99.94%) | 210Rn | 0+ |  |  |
| 214Ra |  | 88 | 126 | 214.000108(10) | 2.46(3) s | β+ (.06%) | 214Fr | 0+ |  |  |
| 215Ra |  | 88 | 127 | 215.002720(8) | 1.55(7) ms | α | 211Rn | (9/2+)# |  |  |
| 215m1Ra |  | 1877.8(5) keV | 1877.8(5) keV | 1877.8(5) keV | 7.1(2) µs |  |  | (25/2+) |  |  |
| 215m2Ra |  | 2246.9(5) keV | 2246.9(5) keV | 2246.9(5) keV | 1.39(7) µs |  |  | (29/2−) |  |  |
| 215m3Ra |  | 3756.6(6)+X keV | 3756.6(6)+X keV | 3756.6(6)+X keV | 0.555(10) µs |  |  | (43/2−) |  |  |
| 216Ra |  | 88 | 128 | 216.003533(9) | 182(10) ns | α | 212Rn | 0+ |  |  |
| 216Ra |  | 88 | 128 | 216.003533(9) | 182(10) ns | EC (1×10−8%) | 216Fr | 0+ |  |  |
| 217Ra |  | 88 | 129 | 217.006320(9) | 1.63(17) µs | α | 213Rn | (9/2+) |  |  |
| 218Ra |  | 88 | 130 | 218.007140(12) | 25.2(3) µs | α | 214Rn | 0+ |  |  |
| 218Ra |  | 88 | 130 | 218.007140(12) | 25.2(3) µs | β+β+ (rare) | 218Rn | 0+ |  |  |
| 219Ra |  | 88 | 131 | 219.010085(9) | 10(3) ms | α | 215Rn | (7/2)+ |  |  |
| 220Ra |  | 88 | 132 | 220.011028(10) | 17.9(14) ms | α | 216Rn | 0+ |  |  |
| 221Ra |  | 88 | 133 | 221.013917(5) | 28(2) s | α | 217Rn | 5/2+ |  |  |
| 221Ra |  | 88 | 133 | 221.013917(5) | 28(2) s | CD (1.2×10−10%) | 207Pb 14C | 5/2+ |  |  |
| 222Ra |  | 88 | 134 | 222.015375(5) | 38.0(5) s | α | 218Rn | 0+ | Trace |  |
| 222Ra |  | 88 | 134 | 222.015375(5) | 38.0(5) s | CD (3×10−8%) | 208Pb 14C | 0+ | Trace |  |
| 223Ra | Actinium X | 88 | 135 | 223.0185022(27) | 11.43(5) d | α | 219Rn | 3/2+ | Trace |  |
| 223Ra | Actinium X | 88 | 135 | 223.0185022(27) | 11.43(5) d | CD (6.4×10−8%) | 209Pb 14C | 3/2+ | Trace |  |
| 224Ra | Thorium X | 88 | 136 | 224.0202118(24) | 3.6319(23) d | α | 220Rn | 0+ | Trace |  |
| 224Ra | Thorium X | 88 | 136 | 224.0202118(24) | 3.6319(23) d | CD (4.3×10−9%) | 210Pb 14C | 0+ | Trace |  |
| 225Ra |  | 88 | 137 | 225.023612(3) | 14.9(2) d | β− | 225Ac | 1/2+ |  |  |
| 226Ra | Radium | 88 | 138 | 226.0254098(25) | 1600(7) y | α | 222Rn | 0+ | Trace |  |
| 226Ra | Radium | 88 | 138 | 226.0254098(25) | 1600(7) y | β−β− (rare) | 226Th | 0+ | Trace |  |
| 226Ra | Radium | 88 | 138 | 226.0254098(25) | 1600(7) y | CD (2.6×10−9%) | 212Pb 14C | 0+ | Trace |  |
| 227Ra |  | 88 | 139 | 227.0291778(25) | 42.2(5) min | β− | 227Ac | 3/2+ |  |  |
| 228Ra | Mesothorium 1 | 88 | 140 | 228.0310703(26) | 5.75(3) y | β− | 228Ac | 0+ | Trace |  |
| 229Ra |  | 88 | 141 | 229.034958(20) | 4.0(2) min | β− | 229Ac | 5/2(+) |  |  |
| 230Ra |  | 88 | 142 | 230.037056(13) | 93(2) min | β− | 230Ac | 0+ |  |  |
| 231Ra |  | 88 | 143 | 231.04122(32)# | 103(3) s | β− | 231Ac | (5/2+) |  |  |
| 231mRa |  | 66.21(9) keV | 66.21(9) keV | 66.21(9) keV | ~53 µs |  |  | (1/2+) |  |  |
| 232Ra |  | 88 | 144 | 232.04364(30)# | 250(50) s | β− | 232Ac | 0+ |  |  |
| 233Ra |  | 88 | 145 | 233.04806(50)# | 30(5) s | β− | 233Ac | 1/2+# |  |  |
| 234Ra |  | 88 | 146 | 234.05070(53)# | 30(10) s | β− | 234Ac | 0+ |  |  |