Isotopes of radon
Appearance
(Redirected from Radon-221)
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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 3.8235 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
[edit]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%) | 211At | 1/2− | ||||||||||||
α (27.4%) | 207Po | ||||||||||||||||||
211m1Rn | 1603(14)# keV | 596(28) ns | IT | 211Rn | 17/2− | ||||||||||||||
211m2Rn | 8905(20)# keV | 201(4) ns | IT | 211Rn | 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.
- ^ a b # – 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.
- ^ Theoretically capable of electron capture to 213At[4]
- ^ a b Intermediate decay product of 237Np
- ^ a b Intermediate decay product of 238U
- ^ Intermediate decay product of 235U
- ^ Theorized to also undergo β−β− decay to 220Ra
- ^ Intermediate decay product of 232Th
- ^ Source of element's name
- ^ Theorized to also undergo β− decay to 222Fr[5] and β−β− decay to 222Ra
References
[edit]- ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
- ^ "Decay Chain".
- ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
- ^ "Adopted Levels for 213Rn" (PDF). NNDC Chart of Nuclides.
- ^ Belli, P.; Bernabei, R.; Cappella, C.; Caracciolo, V.; Cerulli, R.; Danevich, F.A.; Di Marco, A.; Incicchitti, A.; Poda, D.V.; Polischuk, O.G.; Tretyak, V.I. (2014). "Investigation of rare nuclear decays with BaF2 crystal scintillator contaminated by radium". European Physical Journal A. 50 (9): 134–143. arXiv:1407.5844. Bibcode:2014EPJA...50..134B. doi:10.1140/epja/i2014-14134-6. S2CID 118513731.
- Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.