Isotopes of radon

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There are 39 known isotopes of radon (Rn) from 193Rn to 231Rn. The most stable isotope is 222Rn with a half-life of 3.823 days. Four isotopes, 218, 219, 220, 222Rn occur in trace quantities in nature as decay products of, respectively, 218At, 223Ra, 224Ra, and 226Ra. 218Rn and 222Rn are intermediate steps in the decay chain for 238U, 219Rn is an intermediate step in the decay chain for 235U and 220Rn occurs in the decay chain for 232Th.

Table[edit]

nuclide
symbol
historic
name
Z(p) N(n)  
isotopic mass (u)
 
half-life decay
mode(s)[1][n 1]
daughter
isotope(s)
nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
195Rn 86 109 195.00544(5) 6 ms 3/2-#
195mRn 50(50) keV 6 ms 13/2+#
196Rn 86 110 196.002115(16) 4.7(11) ms
[4.4(+13-9) ms]
α 192Po 0+
β+ (rare) 196At
197Rn 86 111 197.00158(7) 66(16) ms
[65(+25-14) ms]
α 193Po 3/2-#
β+ (rare) 197At
197mRn 200(60)# keV 21(5) ms
[19(+8-4) ms]
α 193Po (13/2+)
β+ (rare) 197At
198Rn 86 112 197.998679(14) 65(3) ms α (99%) 194Po 0+
β+ (1%) 198At
199Rn 86 113 198.99837(7) 620(30) ms α (94%) 195Po 3/2-#
β+ (6%) 199At
199mRn 180(70) keV 320(20) ms α (97%) 195Po 13/2+#
β+ (3%) 199At
200Rn 86 114 199.995699(14) 0.96(3) s α (98%) 196Po 0+
β+ (2%) 200At
201Rn 86 115 200.99563(8) 7.0(4) s α (80%) 197Po (3/2-)
β+ (20%) 201At
201mRn 280(90)# keV 3.8(1) s α (90%) 197Po (13/2+)
β+ (10%) 201At
IT (<1%) 201Rn
202Rn 86 116 201.993263(19) 9.94(18) s α (85%) 198Po 0+
β+ (15%) 202At
203Rn 86 117 202.993387(25) 44.2(16) s α (66%) 199Po (3/2-)
β+ (34%) 203At
203mRn 363(4) keV 26.7(5) s α (80%) 199Po 13/2(+)
β+ (20%) 203At
204Rn 86 118 203.991429(16) 1.17(18) min α (73%) 200Po 0+
β+ (27%) 204At
205Rn 86 119 204.99172(5) 170(4) s β+ (77%) 205At 5/2-
α (23%) 201Po
206Rn 86 120 205.990214(16) 5.67(17) min α (62%) 202Po 0+
β+ (38%) 206At
207Rn 86 121 206.990734(28) 9.25(17) min β+ (79%) 207At 5/2-
α (21%) 203Po
207mRn 899.0(10) keV 181(18) µs (13/2+)
208Rn 86 122 207.989642(12) 24.35(14) min α (62%) 204Po 0+
β+ (38%) 208At
209Rn 86 123 208.990415(21) 28.5(10) min β+ (83%) 209At 5/2-
α (17%) 205Po
209m1Rn 1173.98(13) keV 13.4(13) µs 13/2+
209m2Rn 3636.78(23) keV 3.0(3) µs (35/2+)
210Rn 86 124 209.989696(9) 2.4(1) h α (96%) 206Po 0+
β+ (4%) 210At
210m1Rn 1690(15) keV 644(40) ns 8+#
210m2Rn 3837(15) keV 1.06(5) µs (17)-
210m3Rn 6493(15) keV 1.04(7) µs (22)+
211Rn 86 125 210.990601(7) 14.6(2) h α (72.6%) 207Po 1/2-
β+ (27.4%) 211At
212Rn 86 126 211.990704(3) 23.9(12) min α 208Po 0+
β+β+ (rare) 212Po
213Rn 86 127 212.993883(6) 19.5(1) ms α 209Po (9/2+)
214Rn 86 128 213.995363(10) 0.27(2) µs α 210Po 0+
β+β+ (rare) 214Po
214mRn 4595.4 keV 245(30) ns (22+)
215Rn 86 129 214.998745(8) 2.30(10) µs α 211Po 9/2+
216Rn 86 130 216.000274(8) 45(5) µs α 212Po 0+
217Rn 86 131 217.003928(5) 0.54(5) ms α 213Po 9/2+
218Rn 86 132 218.0056013(25) 35(5) ms α 214Po 0+ Trace[n 2]
219Rn Actinon
Actinium emanation
86 133 219.0094802(27) 3.96(1) s α 215Po 5/2+ Trace[n 3]
220Rn Thoron
Thorium emanation
86 134 220.0113940(24) 55.6(1) s α 216Po 0+ Trace[n 4]
β-β- (rare) 220Ra
221Rn 86 135 221.015537(6) 25.7(5) min β- (78%) 221Fr 7/2(+)
α (22%) 217Po
222Rn Radon[n 5]
Radium emanation
Emanation
Emanon
Niton
86 136 222.0175777(25) 3.8235(3) d α 218Po 0+ Trace[n 2]
223Rn 86 137 223.02179(32)# 24.3(4) min β- 223Fr 7/2
224Rn 86 138 224.02409(32)# 107(3) min β- 224Fr 0+
225Rn 86 139 225.02844(32)# 4.66(4) min β- 225Fr 7/2-
226Rn 86 140 226.03089(43)# 7.4(1) min β- 226Fr 0+
227Rn 86 141 227.03541(45)# 20.8(7) s β- 227Fr 5/2(+#)
228Rn 86 142 228.03799(44)# 65(2) s β- 228Fr 0+
229Rn 86 143 229.0426536(141) 12 s
  1. ^ Abbreviations:
    IT: Isomeric transition
  2. ^ a b Intermediate decay product of 238U
  3. ^ Intermediate decay product of 235U
  4. ^ Intermediate decay product of 232Th
  5. ^ Source of element's name

Notes[edit]

  • 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[edit]

  1. ^ http://www.nucleonica.net/unc.aspx


Isotopes of astatine Isotopes of radon Isotopes of francium
Table of nuclides