Isotopes of radium
Appearance
Radium (Ra) has no stable or nearly stable isotopes, and thus a standard atomic mass cannot be given. The longest lived, and most common, isotope of radium is 226Ra with a half-life of 1600 years. 226Ra occurs in the disintegration chain of 238U (often referred to as the radium series.) Radium has 35 known isotopes from 201Ra to 235Ra, with the newest being 235Ra.
Table
nuclide symbol |
historic name |
Z(p) | N(n) | isotopic mass (u) |
half-life | decay mode(s)[1][n 1] |
daughter isotope(s)[n 2] |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
---|---|---|---|---|---|---|---|---|---|---|
excitation energy | ||||||||||
202Ra | 88 | 114 | 202.00989(7) | 2.6(21) ms [0.7(+33-3) ms] |
0+ | |||||
203Ra | 88 | 115 | 203.00927(9) | 4(3) ms | α | 199Rn | (3/2-) | |||
β+ (rare) | 203Fr | |||||||||
203mRa | 220(90) keV | 41(17) ms | α | 199Rn | (13/2+) | |||||
β+ (rare) | 203Fr | |||||||||
204Ra | 88 | 116 | 204.006500(17) | 60(11) ms [59(+12-9) ms] |
α (99.7%) | 200Rn | 0+ | |||
β+ (.3%) | 204Fr | |||||||||
205Ra | 88 | 117 | 205.00627(9) | 220(40) ms [210(+60-40) ms] |
α | 201Rn | (3/2-) | |||
β+ (rare) | 205Fr | |||||||||
205mRa | 310(110)# keV | 180(50) ms [170(+60-40) ms] |
α | 201Rn | (13/2+) | |||||
IT (rare) | 205Ra | |||||||||
206Ra | 88 | 118 | 206.003827(19) | 0.24(2) s | α | 202Rn | 0+ | |||
207Ra | 88 | 119 | 207.00380(6) | 1.3(2) s | α (90%) | 203Rn | (5/2-,3/2-) | |||
β+ (10%) | 207Fr | |||||||||
207mRa | 560(50) keV | 57(8) ms | IT (85%) | 207Ra | (13/2+) | |||||
α (15%) | 203Rn | |||||||||
β+ (.55%) | 207Fr | |||||||||
208Ra | 88 | 120 | 208.001840(17) | 1.3(2) s | α (95%) | 204Rn | 0+ | |||
β+ (5%) | 208Fr | |||||||||
208mRa | 1800(200) keV | 270 ns | (8+) | |||||||
209Ra | 88 | 121 | 209.00199(5) | 4.6(2) s | α (90%) | 205Rn | 5/2- | |||
β+ (10%) | 209Fr | |||||||||
210Ra | 88 | 122 | 210.000495(16) | 3.7(2) s | α (96%) | 206Rn | 0+ | |||
β+ (4%) | 210Fr | |||||||||
210mRa | 1800(200) keV | 2.24 µs | (8+) | |||||||
211Ra | 88 | 123 | 211.000898(28) | 13(2) s | α (97%) | 207Rn | 5/2(-) | |||
β+ (3%) | 211Fr | |||||||||
212Ra | 88 | 124 | 211.999794(12) | 13.0(2) s | α (85%) | 208Rn | 0+ | |||
β+ (15%) | 212Fr | |||||||||
212m1Ra | 1958.4(5) keV | 10.9(4) µs | (8)+ | |||||||
212m2Ra | 2613.4(5) keV | 0.85(13) µs | (11)- | |||||||
213Ra | 88 | 125 | 213.000384(22) | 2.74(6) min | α (80%) | 209Rn | 1/2- | |||
β+ (20%) | 213Fr | |||||||||
213mRa | 1769(6) keV | 2.1(1) ms | IT (99%) | 213Ra | 17/2-# | |||||
α (1%) | 209Rn | |||||||||
214Ra | 88 | 126 | 214.000108(10) | 2.46(3) s | α (99.94%) | 210Rn | 0+ | |||
β+ (.06%) | 214Fr | |||||||||
215Ra | 88 | 127 | 215.002720(8) | 1.55(7) ms | α | 211Rn | (9/2+)# | |||
215m1Ra | 1877.8(5) keV | 7.1(2) µs | (25/2+) | |||||||
215m2Ra | 2246.9(5) keV | 1.39(7) µs | (29/2-) | |||||||
215m3Ra | 3756.6(6)+X keV | 0.555(10) µs | (43/2-) | |||||||
216Ra | 88 | 128 | 216.003533(9) | 182(10) ns | α | 212Rn | 0+ | |||
EC (1×10−8%) | 216Fr | |||||||||
217Ra | 88 | 129 | 217.006320(9) | 1.63(17) µs | α | 213Rn | (9/2+) | |||
218Ra | 88 | 130 | 218.007140(12) | 25.2(3) µs | α | 214Rn | 0+ | |||
β+β+ (rare) | 218Rn | |||||||||
219Ra | 88 | 131 | 219.010085(9) | 10(3) ms | α | 215Rn | (7/2)+ | |||
220Ra | 88 | 132 | 220.011028(10) | 17.9(14) ms | α | 216Rn | 0+ | |||
221Ra | 88 | 133 | 221.013917(5) | 28(2) s | α | 217Rn | 5/2+ | |||
CD (1.2×10−10%) | 207Pb 14C | |||||||||
222Ra | 88 | 134 | 222.015375(5) | 38.0(5) s | α | 218Rn | 0+ | |||
CD (3×10−8%) | 208Pb 14C | |||||||||
223Ra | Actinium X | 88 | 135 | 223.0185022(27) | 11.43(5) d | α | 219Rn | 3/2+ | Trace[n 3] | |
CD (6.4×10−8%) | 209Pb 14C | |||||||||
224Ra | Thorium X | 88 | 136 | 224.0202118(24) | 3.6319(23) d | α | 220Rn | 0+ | Trace[n 4] | |
CD (4.3×10−9%) | 210Pb 14C | |||||||||
225Ra | 88 | 137 | 225.023612(3) | 14.9(2) d | β- | 225Ac | 1/2+ | |||
226Ra | Radium[n 5] | 88 | 138 | 226.0254098(25) | 1600(7) y | α | 222Rn | 0+ | Trace[n 6] | |
β-β- (rare) | 226Th | |||||||||
CD (2.6×10−9%) | 212Pb 14C | |||||||||
227Ra | 88 | 139 | 227.0291778(25) | 42.2(5) min | β- | 227Ac | 3/2+ | |||
228Ra | Mesothorium 1 | 88 | 140 | 228.0310703(26) | 5.75(3) y | β- | 228Ac | 0+ | Trace[n 4] | |
229Ra | 88 | 141 | 229.034958(20) | 4.0(2) min | β- | 229Ac | 5/2(+) | |||
230Ra | 88 | 142 | 230.037056(13) | 93(2) min | β- | 230Ac | 0+ | |||
231Ra | 88 | 143 | 231.04122(32)# | 103(3) s | β- | 231Ac | (5/2+) | |||
231mRa | 66.21(9) keV | ~53 µs | (1/2+) | |||||||
232Ra | 88 | 144 | 232.04364(30)# | 250(50) s | β- | 232Ac | 0+ | |||
233Ra | 88 | 145 | 233.04806(50)# | 30(5) s | β- | 233Ac | 1/2+# | |||
234Ra | 88 | 146 | 234.05070(53)# | 30(10) s | β- | 234Ac | 0+ |
- ^ Abbreviations:
CD: Cluster decay
EC: Electron capture
IT: Isomeric transition - ^ Bold for stable isotopes
- ^ Intermediate decay product of 235U
- ^ a b Intermediate decay product of 232Th
- ^ Source of element's name
- ^ Intermediate decay product of 238U
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
- Isotope masses from:
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). 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:
- 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.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - 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.
{{cite journal}}
: Unknown parameter|laysummary=
ignored (help)
- 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.
- 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" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
{{cite web}}
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(help) - N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide (ed.). CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.
{{cite book}}
: Unknown parameter|nopp=
ignored (|no-pp=
suggested) (help)
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.