Isotopes of radon

There are 37 known isotopes of radon (₈₆Rn), from ¹⁹⁵Rn to ²³¹Rn; all are radioactive. The most stable isotope is ²²²Rn with a half-life of 3.823 days, which decays into ²¹⁸
Po
. Five isotopes of radon, ^{217, 218, 219, 220, 222}Rn occur in trace quantities in nature as decay products of, respectively, ²¹⁷At, ²¹⁸At, ²²³Ra, ²²⁴Ra, and ²²⁶Ra. ²¹⁷Rn is produced in a rare branch in the decay chain of trace quantities of ²³⁷Np; 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.

Main isotopes of radon (₈₆Rn)

Iso­tope Decay abun­dance half-life (t1/2) mode pro­duct ^210Rn syn 2.4 h α ^206Po ^211Rn syn 14.6 h ε ^211At α ^207Po ^222Rn trace 3.8235 d α ^218Po ^224Rn syn 1.8 h β^− ^224Fr

List of isotopes

Nuclide [n 1]	Historic name	Z	N	Isotopic mass (Da) [n 2][n 3]	Half-life	Decay mode	Daughter isotope	Spin and parity [n 4][n 5]	Isotopic abundance
		Excitation energy[n 5]
^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(+23−14) 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+	Trace[n 6]
^218Rn		86	132	218.0056013(25)	35(5) ms	α	^214Po	0+	Trace[n 7]
^219Rn	Actinon Actinium emanation	86	133	219.0094802(27)	3.96(1) s	α	^215Po	5/2+	Trace[n 8]
^220Rn	Thoron Thorium emanation	86	134	220.0113940(24)	55.6(1) s	α	^216Po	0+	Trace[n 9]
						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 10] Radium emanation Emanation Emanon Niton	86	136	222.0175777(25)	3.8235(3) d	α	^218Po	0+	Trace[n 7]
^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[1]		86	143	229.0426536(141)	12(1) s	β^−	^229Fr
^230Rn[2]		86	144			β^−	^230Fr	0+
^231Rn[3]		86	145			β^−	^231Fr

1. ^mRn – Excited nuclear isomer.
2. ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
3. # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
4. ( ) spin value – Indicates spin with weak assignment arguments.
5. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
6. Intermediate decay product of ²³⁷Np
7. Intermediate decay product of ²³⁸U
8. Intermediate decay product of ²³⁵U
9. Intermediate decay product of ²³²Th
10. Source of element's name

References

1. Neidherr, D.; Audi, G.; Beck, D.; Baum, K.; Böhm, Ch.; Breitenfeldt, M.; Cakirli, R. B.; Casten, R. F.; George, S.; Herfurth, F.; Herlert, A.; Kellerbauer, A.; Kowalska, M.; Lunney, D.; Minaya-Ramirez, E.; Naimi, S.; Noah, E.; Penescu, L.; Rosenbusch, M.; Schwarz, S.; Schweikhard, L.; Stora, T. (19 March 2009). "Discovery of ²²⁹Rn and the Structure of the Heaviest Rn and Ra Isotopes from Penning-Trap Mass Measurements" (PDF). Physical Review Letters. 102 (11): 112501–1–112501–5. Bibcode:2009PhRvL.102k2501N. doi:10.1103/PhysRevLett.102.112501. PMID 19392194.
3. "

• 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
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
• 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.