# Isotopes of radon

There are 39 known isotopes of radon ($_{86}$Rn), from $^{193}$Rn to $^{231}$Rn; all are radioactive. The most stable isotope is $^{222}$Rn with a half-life of 3.8235 days, which decays into $^{218}$ Po . Six isotopes of radon, $^{217,218,219,220,221,222}$Rn, occur in trace quantities in nature as decay products of, respectively, $^{217}$At, $^{218}$At, $^{223}$Ra, $^{224}$Ra, $^{225}$Ra, and $^{226}$Ra. $^{217}$Rn and $^{221}$Rn are produced in rare branches in the decay chain of trace quantities of $^{237}$Np; $^{222}$Rn (and also $^{218}$Rn in a rare branch) is an intermediate step in the decay chain of $^{238}$U; $^{219}$Rn is an intermediate step in the decay chain of $^{235}$U; and $^{220}$Rn occurs in the decay chain of $^{232}$Th.

## List of isotopes

| Nuclide | Historic name | Z | N | Isotopic mass (Da) | Half-life | Decay mode | Daughter isotope | Spin and parity | Isotopic abundance |
| Isotopic abundance |||
| $^{193}$Rn | | 86 | 107 | 193.009708(27) | 1.15(27) ms | α | $^{189}$Po | (3/2−) | |
| $^{194}$Rn | | 86 | 108 | 194.006146(18) | 0.78(16) ms | α | $^{190}$Po | 0+ | |
| $^{194}$Rn | | 86 | 108 | 194.006146(18) | 0.78(16) ms | β$^+$? | $^{194}$At | 0+ | |
| $^{195}$Rn | | 86 | 109 | 195.005422(55) | 7(3) ms | α | $^{191}$Po | 3/2− | |
| $^{195m}$Rn | | 80(50) keV | 80(50) keV | 80(50) keV | 6(3) ms | α | $^{191}$Po | 13/2+ | |
| $^{196}$Rn | | 86 | 110 | 196.002120(15) | 4.7(11) ms | α | $^{192}$Po | 0+ | |
| $^{196}$Rn | | 86 | 110 | 196.002120(15) | 4.7(11) ms | β$^+$? | $^{196}$At | 0+ | |
| $^{197}$Rn | | 86 | 111 | 197.001621(17) | 54(6) ms | α | $^{193}$Po | 3/2− | |
| $^{197}$Rn | | 86 | 111 | 197.001621(17) | 54(6) ms | β$^+$? | $^{197}$At | 3/2− | |
| $^{197m}$Rn | | 199(11) keV | 199(11) keV | 199(11) keV | 25.6(25) ms | α | $^{193}$Po | 13/2+ | |
| $^{197m}$Rn | | 199(11) keV | 199(11) keV | 199(11) keV | 25.6(25) ms | β$^+$? | $^{197}$At | 13/2+ | |
| $^{198}$Rn | | 86 | 112 | 197.998679(14) | 64.4(16) ms | α (93%) | $^{194}$Po | 0+ | |
| $^{198}$Rn | | 86 | 112 | 197.998679(14) | 64.4(16) ms | β$^+$? (7%) | $^{198}$At | 0+ | |
| $^{199}$Rn | | 86 | 113 | 198.9983254(78) | 590(30) ms | α | $^{195}$Po | 3/2− | |
| $^{199}$Rn | | 86 | 113 | 198.9983254(78) | 590(30) ms | β$^+$? | $^{199}$At | 3/2− | |
| $^{199m}$Rn | | 220(11) keV | 220(11) keV | 220(11) keV | 310(20) ms | α | $^{195}$Po | 13/2+ | |
| $^{199m}$Rn | | 220(11) keV | 220(11) keV | 220(11) keV | 310(20) ms | β$^+$? | $^{199}$At | 13/2+ | |
| $^{199m}$Rn | | 220(11) keV | 220(11) keV | 220(11) keV | 310(20) ms | IT? | $^{199}$At | 13/2+ | |
| $^{200}$Rn | | 86 | 114 | 199.9957053(62) | 1.09(16) s | α (92%) | $^{196}$Po | 0+ | |
| $^{200}$Rn | | 86 | 114 | 199.9957053(62) | 1.09(16) s | β$^+$? (8%) | $^{200}$At | 0+ | |
| $^{200m}$Rn | | 2320(20)# keV | 2320(20)# keV | 2320(20)# keV | 28(9) μs | IT | $^{200}$Rn | | |
| $^{201}$Rn | | 86 | 115 | 200.995591(11) | 7.0(4) s | α | $^{197}$Po | 3/2− | |
| $^{201}$Rn | | 86 | 115 | 200.995591(11) | 7.0(4) s | β$^+$? | $^{201}$At | 3/2− | |
| $^{201m}$Rn | | 245(12) keV | 245(12) keV | 245(12) keV | 3.8(1) s | α | $^{197}$Po | 13/2+ | |
| $^{201m}$Rn | | 245(12) keV | 245(12) keV | 245(12) keV | 3.8(1) s | β$^+$? | $^{201}$At | 13/2+ | |
| $^{202}$Rn | | 86 | 116 | 201.993264(19) | 9.7(1) s | α (78%) | $^{198}$Po | 0+ | |
| $^{202}$Rn | | 86 | 116 | 201.993264(19) | 9.7(1) s | β$^+$ (22%) | $^{202}$At | 0+ | |
| $^{202m}$Rn | | 2310(50)# keV | 2310(50)# keV | 2310(50)# keV | 2.22(7) μs | IT | $^{202}$Rn | 11−# | |
| $^{203}$Rn | | 86 | 117 | 202.9933612(62) | 44.2(16) s | α (66%) | $^{199}$Po | 3/2− | |
| $^{203}$Rn | | 86 | 117 | 202.9933612(62) | 44.2(16) s | β$^+$ (34%) | $^{203}$At | 3/2− | |
| $^{203m}$Rn | | 362(4) keV | 362(4) keV | 362(4) keV | 26.9(5) s | α (75%) | $^{199}$Po | 13/2+ | |
| $^{203m}$Rn | | 362(4) keV | 362(4) keV | 362(4) keV | 26.9(5) s | β$^+$ (25%) | $^{203}$At | 13/2+ | |
| $^{204}$Rn | | 86 | 118 | 203.9914437(80) | 1.242(23) min | α (72.4%) | $^{200}$Po | 0+ | |
| $^{204}$Rn | | 86 | 118 | 203.9914437(80) | 1.242(23) min | β$^+$ (27.6%) | $^{204}$At | 0+ | |
| $^{205}$Rn | | 86 | 119 | 204.9917232(55) | 170(4) s | β$^+$ (75.4%) | $^{205}$At | 5/2− | |
| $^{205}$Rn | | 86 | 119 | 204.9917232(55) | 170(4) s | α (24.6%) | $^{201}$Po | 5/2− | |
| $^{205m}$Rn | | 657.1(5) keV | 657.1(5) keV | 657.1(5) keV | >10 s | IT | $^{205}$Rn | 13/2+# | |
| $^{205m}$Rn | | 657.1(5) keV | 657.1(5) keV | 657.1(5) keV | >10 s | α? | $^{201}$Po | 13/2+# | |
| $^{205m}$Rn | | 657.1(5) keV | 657.1(5) keV | 657.1(5) keV | >10 s | β$^+$? | $^{205}$At | 13/2+# | |
| $^{206}$Rn | | 86 | 120 | 205.9901954(92) | 5.67(17) min | α (62%) | $^{202}$Po | 0+ | |
| $^{206}$Rn | | 86 | 120 | 205.9901954(92) | 5.67(17) min | β$^+$ (38%) | $^{206}$At | 0+ | |
| $^{207}$Rn | | 86 | 121 | 206.9907302(51) | 9.25(17) min | β$^+$ (79%) | $^{207}$At | 5/2− | |
| $^{207}$Rn | | 86 | 121 | 206.9907302(51) | 9.25(17) min | α (21%) | $^{203}$Po | 5/2− | |
| $^{207m}$Rn | | 899.1(10) keV | 899.1(10) keV | 899.1(10) keV | 184.5(9) μs | IT | $^{207}$Rn | 13/2+ | |
| $^{208}$Rn | | 86 | 122 | 207.989635(11) | 24.35(14) min | α (62%) | $^{204}$Po | 0+ | |
| $^{208}$Rn | | 86 | 122 | 207.989635(11) | 24.35(14) min | β$^+$ (38%) | $^{208}$At | 0+ | |
| $^{208m}$Rn | | 1828.3(4) keV | 1828.3(4) keV | 1828.3(4) keV | 487(12) ns | IT | $^{208}$Rn | 8+ | |
| $^{209}$Rn | | 86 | 123 | 208.990401(11) | 28.8(10) min | β$^+$ (83%) | $^{209}$At | 5/2− | |
| $^{209}$Rn | | 86 | 123 | 208.990401(11) | 28.8(10) min | α (17%) | $^{205}$Po | 5/2− | |
| $^{209m1}$Rn | | 1174.01(13) keV | 1174.01(13) keV | 1174.01(13) keV | 13.4(13) μs | IT | $^{209}$Rn | 13/2+ | |
| $^{209m2}$Rn | | 3636.81(23) keV | 3636.81(23) keV | 3636.81(23) keV | 3.0(3) μs | IT | $^{209}$Rn | 35/2+ | |
| $^{210}$Rn | | 86 | 124 | 209.9896889(49) | 2.4(1) h | α (96%) | $^{206}$Po | 0+ | |
| $^{210}$Rn | | 86 | 124 | 209.9896889(49) | 2.4(1) h | β$^+$ (4%) | $^{210}$At | 0+ | |
| $^{210m1}$Rn | | 1710(30) keV | 1710(30) keV | 1710(30) keV | 644(40) ns | IT | $^{210}$Rn | 8+ | |
| $^{210m2}$Rn | | 3857(30) keV | 3857(30) keV | 3857(30) keV | 1.06(5) μs | IT | $^{210}$Rn | 17− | |
| $^{210m3}$Rn | | 6514(30) keV | 6514(30) keV | 6514(30) keV | 1.04(7) μs | IT | $^{210}$Rn | 23+ | |
| $^{211}$Rn | | 86 | 125 | 210.9906008(73) | 14.6(2) h | β$^+$ (72.6%) | $^{211}$At | 1/2− | |
| $^{211}$Rn | | 86 | 125 | 210.9906008(73) | 14.6(2) h | α (27.4%) | $^{207}$Po | 1/2− | |
| $^{211m1}$Rn | | 1603(14)# keV | 1603(14)# keV | 1603(14)# keV | 596(28) ns | IT | $^{211}$Rn | 17/2− | |
| $^{211m2}$Rn | | 8905(20)# keV | 8905(20)# keV | 8905(20)# keV | 201(4) ns | IT | $^{211}$Rn | 63/2− | |
| $^{212}$Rn | | 86 | 126 | 211.9907039(33) | 23.9(12) min | α | $^{208}$Po | 0+ | |
| $^{212m1}$Rn | | 1639.68(15) keV | 1639.68(15) keV | 1639.68(15) keV | 118(14) ns | IT | $^{212}$Rn | 6+ | |
| $^{212m2}$Rn | | 1694.1(3) keV | 1694.1(3) keV | 1694.1(3) keV | 910(30) ns | IT | $^{212}$Rn | 8+ | |
| $^{212m3}$Rn | | 6174.2(3) keV | 6174.2(3) keV | 6174.2(3) keV | 102(4) ns | IT | $^{212}$Rn | 22+ | |
| $^{212m4}$Rn | | 8579.2(4) keV | 8579.2(4) keV | 8579.2(4) keV | 154(14) ns | IT | $^{212}$Rn | 30+ | |
| $^{213}$Rn | | 86 | 127 | 212.9938851(36) | 19.5(1) ms | α | $^{209}$Po | 9/2+# | |
| $^{213m1}$Rn | | 1682(10) keV | 1682(10) keV | 1682(10) keV | 1.00(21) μs | IT | $^{213}$Rn | (25/2+) | |
| $^{213m2}$Rn | | 2205(10) keV | 2205(10) keV | 2205(10) keV | 1.36(7) μs | IT | $^{213}$Rn | (31/2−) | |
| $^{213m3}$Rn | | 5965(14) keV | 5965(14) keV | 5965(14) keV | 164(11) ns | IT | $^{213}$Rn | (55/2+) | |
| $^{214}$Rn | | 86 | 128 | 213.9953627(99) | 259(3) ns | α | $^{210}$Po | 0+ | |
| $^{214m}$Rn | | 4595.4(18) keV | 4595.4(18) keV | 4595.4(18) keV | 245(30) ns | IT | $^{214}$Rn | (22+) | |
| $^{215}$Rn | | 86 | 129 | 214.9987450(65) | 2.30(10) μs | α | $^{211}$Po | 9/2+ | |
| $^{216}$Rn | | 86 | 130 | 216.0002719(62) | 29(4) μs | α | $^{212}$Po | 0+ | |
| $^{217}$Rn | | 86 | 131 | 217.0039276(45) | 593(38) μs | α | $^{213}$Po | 9/2+ | Trace |
| $^{218}$Rn | | 86 | 132 | 218.0056011(25) | 33.75(15) ms | α | $^{214}$Po | 0+ | Trace |
| $^{219}$Rn | Actinon Actinium emanation | 86 | 133 | 219.0094787(23) | 3.96(1) s | α | $^{215}$Po | 5/2+ | Trace |
| $^{220}$Rn | Thoron Thorium emanation | 86 | 134 | 220.0113924(19) | 55.6(1) s | α | $^{216}$Po | 0+ | Trace |
| $^{221}$Rn | | 86 | 135 | 221.0155356(61) | 25.7(5) min | β$^−$ (78%) | $^{221}$Fr | 7/2+ | Trace |
| $^{221}$Rn | | 86 | 135 | 221.0155356(61) | 25.7(5) min | α (22%) | $^{217}$Po | 7/2+ | Trace |
| $^{222}$Rn | Radon Radium emanation Emanation Emanon Niton | 86 | 136 | 222.0175760(21) | 3.8215(2) d | α | $^{218}$Po | 0+ | Trace |
| $^{223}$Rn | | 86 | 137 | 223.0218893(84) | 24.3(4) min | β$^−$ | $^{223}$Fr | 7/2+ | |
| $^{223}$Rn | | 86 | 137 | 223.0218893(84) | 24.3(4) min | α? | $^{219}$Po | 7/2+ | |
| $^{224}$Rn | | 86 | 138 | 224.024096(11) | 107(3) min | β$^−$ | $^{224}$Fr | 0+ | |
| $^{225}$Rn | | 86 | 139 | 225.028486(12) | 4.66(4) min | β$^−$ | $^{225}$Fr | 7/2− | |
| $^{226}$Rn | | 86 | 140 | 226.030861(11) | 7.4(1) min | β$^−$ | $^{226}$Fr | 0+ | |
| $^{227}$Rn | | 86 | 141 | 227.035304(15) | 20.2(4) s | β$^−$ | $^{227}$Fr | (3/2+) | |
| $^{228}$Rn | | 86 | 142 | 228.037835(19) | 65(2) s | β$^−$ | $^{228}$Fr | 0+ | |
| $^{229}$Rn | | 86 | 143 | 229.042257(14) | 11.9(13) s | β$^−$ | $^{229}$Fr | (5/2+) | |
| $^{230}$Rn | | 86 | 144 | 230.04527(22)# | 24# [>300 ns] | β$^−$? | $^{230}$Fr | 0+ | |
| $^{231}$Rn | | 86 | 145 | 231.04997(32)# | 2# s [>300 ns] | β$^−$? | $^{231}$Fr | 1/2+# | |
| This table header & footer: view ||||||||||
* ↑ $^m$Rn – 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.
* 1 2 # – 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 $^{213}$At
* 1 2 Intermediate decay product of $^{237}$Np
* 1 2 Intermediate decay product of $^{238}$U
* ↑ Intermediate decay product of $^{235}$U
* ↑ Theorized to also undergo β$^−$β$^−$ decay to $^{220}$Ra
* ↑ Intermediate decay product of $^{232}$Th
* ↑ Source of element's name
* ↑ Theorized to also undergo β$^−$ decay to $^{222}$Fr and β$^−$β$^−$ decay to $^{222}$Ra