Isotopes of radon

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, 222}Rn 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

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)
nuclide symbol	historic name	excitation energy			half-life	decay mode(s)^[1]^{[n 1]}	daughter isotope(s)	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
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+
¹⁹⁶Rn		86	110	196.002115(16)	4.7(11) ms [4.4(+13-9) ms]	β⁺ (rare)	¹⁹⁶At	0+
¹⁹⁷Rn		86	111	197.00158(7)	66(16) ms [65(+25-14) ms]	α	¹⁹³Po	3/2-#
¹⁹⁷Rn		86	111	197.00158(7)	66(16) ms [65(+25-14) ms]	β⁺ (rare)	¹⁹⁷At	3/2-#
^197mRn		200(60)# keV			21(5) ms [19(+8-4) ms]	α	¹⁹³Po	(13/2+)
^197mRn		200(60)# keV			21(5) ms [19(+8-4) ms]	β⁺ (rare)	¹⁹⁷At	(13/2+)
¹⁹⁸Rn		86	112	197.998679(14)	65(3) ms	α (99%)	¹⁹⁴Po	0+
¹⁹⁸Rn		86	112	197.998679(14)	65(3) ms	β⁺ (1%)	¹⁹⁸At	0+
¹⁹⁹Rn		86	113	198.99837(7)	620(30) ms	α (94%)	¹⁹⁵Po	3/2-#
¹⁹⁹Rn		86	113	198.99837(7)	620(30) ms	β⁺ (6%)	¹⁹⁹At	3/2-#
^199mRn		180(70) keV			320(20) ms	α (97%)	¹⁹⁵Po	13/2+#
^199mRn		180(70) keV			320(20) ms	β⁺ (3%)	¹⁹⁹At	13/2+#
²⁰⁰Rn		86	114	199.995699(14)	0.96(3) s	α (98%)	¹⁹⁶Po	0+
²⁰⁰Rn		86	114	199.995699(14)	0.96(3) s	β⁺ (2%)	²⁰⁰At	0+
²⁰¹Rn		86	115	200.99563(8)	7.0(4) s	α (80%)	¹⁹⁷Po	(3/2-)
²⁰¹Rn		86	115	200.99563(8)	7.0(4) s	β⁺ (20%)	²⁰¹At	(3/2-)
^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+
²⁰²Rn		86	116	201.993263(19)	9.94(18) s	β⁺ (15%)	²⁰²At	0+
²⁰³Rn		86	117	202.993387(25)	44.2(16) s	α (66%)	¹⁹⁹Po	(3/2-)
²⁰³Rn		86	117	202.993387(25)	44.2(16) s	β⁺ (34%)	²⁰³At	(3/2-)
^203mRn		363(4) keV			26.7(5) s	α (80%)	¹⁹⁹Po	13/2(+)
^203mRn		363(4) keV			26.7(5) s	β⁺ (20%)	²⁰³At	13/2(+)
²⁰⁴Rn		86	118	203.991429(16)	1.17(18) min	α (73%)	²⁰⁰Po	0+
²⁰⁴Rn		86	118	203.991429(16)	1.17(18) min	β⁺ (27%)	²⁰⁴At	0+
²⁰⁵Rn		86	119	204.99172(5)	170(4) s	β⁺ (77%)	²⁰⁵At	5/2-
²⁰⁵Rn		86	119	204.99172(5)	170(4) s	α (23%)	²⁰¹Po	5/2-
²⁰⁶Rn		86	120	205.990214(16)	5.67(17) min	α (62%)	²⁰²Po	0+
²⁰⁶Rn		86	120	205.990214(16)	5.67(17) min	β⁺ (38%)	²⁰⁶At	0+
²⁰⁷Rn		86	121	206.990734(28)	9.25(17) min	β⁺ (79%)	²⁰⁷At	5/2-
²⁰⁷Rn		86	121	206.990734(28)	9.25(17) min	α (21%)	²⁰³Po	5/2-
^207mRn		899.0(10) keV			181(18) µs			(13/2+)
²⁰⁸Rn		86	122	207.989642(12)	24.35(14) min	α (62%)	²⁰⁴Po	0+
²⁰⁸Rn		86	122	207.989642(12)	24.35(14) min	β⁺ (38%)	²⁰⁸At	0+
²⁰⁹Rn		86	123	208.990415(21)	28.5(10) min	β⁺ (83%)	²⁰⁹At	5/2-
²⁰⁹Rn		86	123	208.990415(21)	28.5(10) min	α (17%)	²⁰⁵Po	5/2-
^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+
²¹⁰Rn		86	124	209.989696(9)	2.4(1) h	β⁺ (4%)	²¹⁰At	0+
^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-
²¹¹Rn		86	125	210.990601(7)	14.6(2) h	β⁺ (27.4%)	²¹¹At	1/2-
²¹²Rn		86	126	211.990704(3)	23.9(12) min	α	²⁰⁸Po	0+
²¹²Rn		86	126	211.990704(3)	23.9(12) min	β⁺β⁺ (rare)	²¹²Po	0+
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+
²¹⁴Rn		86	128	213.995363(10)	0.27(2) µs	β⁺β⁺ (rare)	²¹⁴Po	0+
^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]}
²²⁰Rn	Thoron Thorium emanation	86	134	220.0113940(24)	55.6(1) s	β^-β^- (rare)	²²⁰Ra	0+	Trace^{[n 4]}
²²¹Rn		86	135	221.015537(6)	25.7(5) min	β^- (78%)	²²¹Fr	7/2(+)
²²¹Rn		86	135	221.015537(6)	25.7(5) min	α (22%)	²¹⁷Po	7/2(+)
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

^ Abbreviations:
IT: Isomeric transition
^ ^a ^b Intermediate decay product of ²³⁸U
^ Intermediate decay product of ²³⁵U
^ Intermediate decay product of ²³²Th
^ Source of element's name

Notes

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

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

Isotope masses from:
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (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. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
Isotopic compositions and standard atomic masses from:
- J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683. http://www.iupac.org/publications/pac/75/6/0683/pdf/.
- M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. http://iupac.org/publications/pac/78/11/2051/pdf/. Lay summary.
Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (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. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/. Retrieved September 2005.
- N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0849304859.

Isotopes of astatine	Isotopes of radon	Isotopes of francium
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