There are 39 known isotopes of radon (86Rn), from 193Rn to 231Rn; all are radioactive. The most stable isotope is 222Rn with a half-life of 3.823 days, which decays into 218
Po
. Six isotopes of radon, 217, 218, 219, 220, 221, 222Rn, occur in trace quantities in nature as decay products of, respectively, 217At, 218At, 223Ra, 224Ra, 225Ra, and 226Ra. 217Rn and 221Rn are produced in rare branches in the decay chain of trace quantities of 237Np; 222Rn (and also 218Rn in a rare branch) is an intermediate step in the decay chain of 238U;[2] 219Rn is an intermediate step in the decay chain of 235U; and 220Rn occurs in the decay chain of 232Th.
List of isotopes
Nuclide [n 1] |
Historic name |
Z | N | Isotopic mass (Da)[3] [n 2][n 3] |
Half-life |
Decay mode |
Daughter isotope |
Spin and parity [n 4][n 5] |
Isotopic abundance | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy[n 5] | |||||||||||||||||||
193Rn | 86 | 107 | 193.009708(27) | 1.15(27) ms | α | 189Po | (3/2−) | ||||||||||||
194Rn | 86 | 108 | 194.006146(18) | 0.78(16) ms | α | 190Po | 0+ | ||||||||||||
β+? | 194At | ||||||||||||||||||
195Rn | 86 | 109 | 195.005422(55) | 7(3) ms | α | 191Po | 3/2− | ||||||||||||
195mRn[n 6] | 80(50) keV | 6(3) ms | α | 191Po | 13/2+ | ||||||||||||||
196Rn | 86 | 110 | 196.002120(15) | 4.7(11) ms | α | 192Po | 0+ | ||||||||||||
β+? | 196At | ||||||||||||||||||
197Rn | 86 | 111 | 197.001621(17) | 54(6) ms | α | 193Po | 3/2− | ||||||||||||
β+? | 197At | ||||||||||||||||||
197mRn | 199(11) keV | 25.6(25) ms | α | 193Po | 13/2+ | ||||||||||||||
β+? | 197At | ||||||||||||||||||
198Rn | 86 | 112 | 197.998679(14) | 64.4(16) ms | α (93%) | 194Po | 0+ | ||||||||||||
β+? (7%) | 198At | ||||||||||||||||||
199Rn | 86 | 113 | 198.9983254(78) | 590(30) ms | α | 195Po | 3/2− | ||||||||||||
β+? | 199At | ||||||||||||||||||
199mRn | 220(11) keV | 310(20) ms | α | 195Po | 13/2+ | ||||||||||||||
β+? | 199At | ||||||||||||||||||
IT? | 199At | ||||||||||||||||||
200Rn | 86 | 114 | 199.9957053(62) | 1.09(16) s | α (92%) | 196Po | 0+ | ||||||||||||
β+? (8%) | 200At | ||||||||||||||||||
200mRn | 2320(20)# keV | 28(9) μs | IT | 200Rn | |||||||||||||||
201Rn | 86 | 115 | 200.995591(11) | 7.0(4) s | α | 197Po | 3/2− | ||||||||||||
β+? | 201At | ||||||||||||||||||
201mRn | 245(12) keV | 3.8(1) s | α | 197Po | 13/2+ | ||||||||||||||
β+? | 201At | ||||||||||||||||||
202Rn | 86 | 116 | 201.993264(19) | 9.7(1) s | α (78%) | 198Po | 0+ | ||||||||||||
β+ (22%) | 202At | ||||||||||||||||||
202mRn | 2310(50)# keV | 2.22(7) μs | IT | 202Rn | 11−# | ||||||||||||||
203Rn | 86 | 117 | 202.9933612(62) | 44.2(16) s | α (66%) | 199Po | 3/2− | ||||||||||||
β+ (34%) | 203At | ||||||||||||||||||
203mRn | 362(4) keV | 26.9(5) s | α (75%) | 199Po | 13/2+ | ||||||||||||||
β+ (25%) | 203At | ||||||||||||||||||
204Rn | 86 | 118 | 203.9914437(80) | 1.242(23) min | α (72.4%) | 200Po | 0+ | ||||||||||||
β+ (27.6%) | 204At | ||||||||||||||||||
205Rn | 86 | 119 | 204.9917232(55) | 170(4) s | β+ (75.4%) | 205At | 5/2− | ||||||||||||
α (24.6%) | 201Po | ||||||||||||||||||
205mRn | 657.1(5) keV | >10 s | IT | 205Rn | 13/2+# | ||||||||||||||
α? | 201Po | ||||||||||||||||||
β+? | 205At | ||||||||||||||||||
206Rn | 86 | 120 | 205.9901954(92) | 5.67(17) min | α (62%) | 202Po | 0+ | ||||||||||||
β+ (38%) | 206At | ||||||||||||||||||
207Rn | 86 | 121 | 206.9907302(51) | 9.25(17) min | β+ (79%) | 207At | 5/2− | ||||||||||||
α (21%) | 203Po | ||||||||||||||||||
207mRn | 899.1(10) keV | 184.5(9) μs | IT | 207Rn | 13/2+ | ||||||||||||||
208Rn | 86 | 122 | 207.989635(11) | 24.35(14) min | α (62%) | 204Po | 0+ | ||||||||||||
β+ (38%) | 208At | ||||||||||||||||||
208mRn | 1828.3(4) keV | 487(12) ns | IT | 208Rn | 8+ | ||||||||||||||
209Rn | 86 | 123 | 208.990401(11) | 28.8(10) min | β+ (83%) | 209At | 5/2− | ||||||||||||
α (17%) | 205Po | ||||||||||||||||||
209m1Rn | 1174.01(13) keV | 13.4(13) μs | IT | 209Rn | 13/2+ | ||||||||||||||
209m2Rn | 3636.81(23) keV | 3.0(3) μs | 209Rn | IT | 35/2+ | ||||||||||||||
210Rn | 86 | 124 | 209.9896889(49) | 2.4(1) h | α (96%) | 206Po | 0+ | ||||||||||||
β+ (4%) | 210At | ||||||||||||||||||
210m1Rn | 1710(30) keV | 644(40) ns | IT | 210Rn | 8+ | ||||||||||||||
210m2Rn | 3857(30) keV | 1.06(5) μs | IT | 210Rn | 17− | ||||||||||||||
210m3Rn | 6514(30) keV | 1.04(7) μs | IT | 210Rn | 23+ | ||||||||||||||
211Rn | 86 | 125 | 210.9906008(73) | 14.6(2) h | β+ (72.6%) | 207Po | 1/2− | ||||||||||||
α (27.4%) | 211At | ||||||||||||||||||
211m1Rn | 1603(14)# keV | 596(28) ns | IT | 211Rn | 17/2− | ||||||||||||||
211m2Rn | 8905(20)# keV | 201(4) ns | IT | 210Rn | 63/2− | ||||||||||||||
212Rn | 86 | 126 | 211.9907039(33) | 23.9(12) min | α | 208Po | 0+ | ||||||||||||
212m1Rn | 1639.68(15) keV | 118(14) ns | IT | 212Rn | 6+ | ||||||||||||||
212m2Rn | 1694.1(3) keV | 910(30) ns | IT | 212Rn | 8+ | ||||||||||||||
212m3Rn | 6174.2(3) keV | 102(4) ns | IT | 212Rn | 22+ | ||||||||||||||
212m4Rn | 8579.2(4) keV | 154(14) ns | IT | 212Rn | 30+ | ||||||||||||||
213Rn | 86 | 127 | 212.9938851(36) | 19.5(1) ms | α[n 7] | 209Po | 9/2+# | ||||||||||||
213m1Rn | 1682(10) keV | 1.00(21) μs | IT | 213Rn | (25/2+) | ||||||||||||||
213m2Rn | 2205(10) keV | 1.36(7) μs | IT | 213Rn | (31/2−) | ||||||||||||||
213m3Rn | 5965(14) keV | 164(11) ns | IT | 213Rn | (55/2+) | ||||||||||||||
214Rn | 86 | 128 | 213.9953627(99) | 259(3) ns | α | 210Po | 0+ | ||||||||||||
214mRn | 4595.4(18) keV | 245(30) ns | IT | 214Rn | (22+) | ||||||||||||||
215Rn | 86 | 129 | 214.9987450(65) | 2.30(10) μs | α | 211Po | 9/2+ | ||||||||||||
216Rn | 86 | 130 | 216.0002719(62) | 29(4) μs | α | 212Po | 0+ | ||||||||||||
217Rn | 86 | 131 | 217.0039276(45) | 593(38) μs | α | 213Po | 9/2+ | Trace[n 8] | |||||||||||
218Rn | 86 | 132 | 218.0056011(25) | 33.75(15) ms | α | 214Po | 0+ | Trace[n 9] | |||||||||||
219Rn | Actinon Actinium emanation |
86 | 133 | 219.0094787(23) | 3.96(1) s | α | 215Po | 5/2+ | Trace[n 10] | ||||||||||
220Rn | Thoron Thorium emanation |
86 | 134 | 220.0113924(19) | 55.6(1) s | α[n 11] | 216Po | 0+ | Trace[n 12] | ||||||||||
221Rn | 86 | 135 | 221.0155356(61) | 25.7(5) min | β− (78%) | 221Fr | 7/2+ | Trace[n 8] | |||||||||||
α (22%) | 217Po | ||||||||||||||||||
222Rn | Radon[n 13] Radium emanation Emanation Emanon Niton |
86 | 136 | 222.0175760(21) | 3.8215(2) d | α[n 14] | 218Po | 0+ | Trace[n 9] | ||||||||||
223Rn | 86 | 137 | 223.0218893(84) | 24.3(4) min | β− | 223Fr | 7/2+ | ||||||||||||
α? | 219Po | ||||||||||||||||||
224Rn | 86 | 138 | 224.024096(11) | 107(3) min | β− | 224Fr | 0+ | ||||||||||||
225Rn | 86 | 139 | 225.028486(12) | 4.66(4) min | β− | 225Fr | 7/2− | ||||||||||||
226Rn | 86 | 140 | 226.030861(11) | 7.4(1) min | β− | 226Fr | 0+ | ||||||||||||
227Rn | 86 | 141 | 227.035304(15) | 20.2(4) s | β− | 227Fr | (3/2+) | ||||||||||||
228Rn | 86 | 142 | 228.037835(19) | 65(2) s | β− | 228Fr | 0+ | ||||||||||||
229Rn | 86 | 143 | 229.042257(14) | 11.9(13) s | β− | 229Fr | (5/2+) | ||||||||||||
230Rn | 86 | 144 | 230.04527(22)# | 24# [>300 ns] |
β−? | 230Fr | 0+ | ||||||||||||
231Rn | 86 | 145 | 231.04997(32)# | 2# s [>300 ns] |
β−? | 231Fr | 1/2+# | ||||||||||||
This table header & footer: |
- mRn – Excited nuclear isomer.
- ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- ( ) spin value – Indicates spin with weak assignment arguments.
- # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- Order of ground state and isomer is uncertain.
- Intermediate decay product of 238U
- Theorized to also undergo β−β− decay to 220Ra
- Source of element's name
References
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