Naturally occurring Cerium (Ce) is composed of 3 stable isotopes and 1 radioactive isotope; 136Ce, 138Ce, 140Ce, and 142Ce with 140Ce being the most abundant (88.48% natural abundance). 27 radioisotopes have been characterized with the most {abundant and/or stable} being 142Ce with a half-life of greater than 5×1016 years, 144Ce with a half-life of 284.893 days, 139Ce with a half-life of 137.640 days, and 141Ce with a half-life of 32.501 days. All of the remaining radioactive isotopes have half-lives that are less than 4 days and the majority of these have half-lives that are less than 10 minutes. This element also has 2 meta states.
Additional recommended knowledge
The isotopes of cerium range in atomic weight from 123 u (123Ce) to 152 u (152Ce).
Standard atomic mass: 140.116(1) u
Table
nuclide
symbol
| Z(p)
| N(n)
|
isotopic mass (u)
| half-life
| nuclear
spin
| representative
isotopic
composition
(mole fraction)
| range of natural
variation
(mole fraction)
|
| excitation energy
|
| 119Ce
| 58
| 61
| 118.95276(64)#
| 200# ms
| 5/2+#
|
|
|
| 120Ce
| 58
| 62
| 119.94664(75)#
| 250# ms
| 0+
|
|
|
| 121Ce
| 58
| 63
| 120.94342(54)#
| 1.1(1) s
| (5/2)(+#)
|
|
|
| 122Ce
| 58
| 64
| 121.93791(43)#
| 2# s
| 0+
|
|
|
| 123Ce
| 58
| 65
| 122.93540(32)#
| 3.8(2) s
| (5/2)(+#)
|
|
|
| 124Ce
| 58
| 66
| 123.93041(32)#
| 9.1(12) s
| 0+
|
|
|
| 125Ce
| 58
| 67
| 124.92844(21)#
| 9.3(3) s
| (7/2-)
|
|
|
| 126Ce
| 58
| 68
| 125.92397(3)
| 51.0(3) s
| 0+
|
|
|
| 127Ce
| 58
| 69
| 126.92273(6)
| 29(2) s
| 5/2+#
|
|
|
| 128Ce
| 58
| 70
| 127.91891(3)
| 3.93(2) min
| 0+
|
|
|
| 129Ce
| 58
| 71
| 128.91810(3)
| 3.5(3) min
| (5/2+)
|
|
|
| 130Ce
| 58
| 72
| 129.91474(3)
| 22.9(5) min
| 0+
|
|
|
| 130mCe
| 2453.6(3) keV
| 100(8) ns
| (7-)
|
|
|
| 131Ce
| 58
| 73
| 130.91442(4)
| 10.2(3) min
| (7/2+)
|
|
|
| 131mCe
| 61.8(1) keV
| 5.0(10) min
| (1/2+)
|
|
|
| 132Ce
| 58
| 74
| 131.911460(22)
| 3.51(11) h
| 0+
|
|
|
| 132mCe
| 2340.8(5) keV
| 9.4(3) ms
| (8-)
|
|
|
| 133Ce
| 58
| 75
| 132.911515(18)
| 97(4) min
| 1/2+
|
|
|
| 133mCe
| 37.1(8) keV
| 4.9(4) h
| 9/2-
|
|
|
| 134Ce
| 58
| 76
| 133.908925(22)
| 3.16(4) d
| 0+
|
|
|
| 135Ce
| 58
| 77
| 134.909151(12)
| 17.7(3) h
| 1/2(+)
|
|
|
| 135mCe
| 445.8(2) keV
| 20(1) s
| (11/2-)
|
|
|
| 136Ce
| 58
| 78
| 135.907172(14)
| STABLE [>38E+15 a]
| 0+
| 0.00185(2)
| 0.00185-0.00186
|
| 136mCe
| 3095.5(4) keV
| 2.2(2) µs
| 10+
|
|
|
| 137Ce
| 58
| 79
| 136.907806(14)
| 9.0(3) h
| 3/2+
|
|
|
| 137mCe
| 254.29(5) keV
| 34.4(3) h
| 11/2-
|
|
|
| 138Ce
| 58
| 80
| 137.905991(11)
| STABLE [>150E+12 a]
| 0+
| 0.00251(2)
| 0.00251-0.00254
|
| 138mCe
| 2129.17(12) keV
| 8.65(20) ms
| 7-
|
|
|
| 139Ce
| 58
| 81
| 138.906653(8)
| 137.641(20) d
| 3/2+
|
|
|
| 139mCe
| 754.24(8) keV
| 56.54(13) s
| 11/2-
|
|
|
| 140Ce
| 58
| 82
| 139.9054387(26)
| STABLE
| 0+
| 0.88450(51)
| 0.88446-0.88449
|
| 140mCe
| 2107.85(3) keV
| 7.3(15) µs
| 6+
|
|
|
| 141Ce
| 58
| 83
| 140.9082763(26)
| 32.508(13) d
| 7/2-
|
|
|
| 142Ce
| 58
| 84
| 141.909244(3)
| STABLE [>50E+15 a]
| 0+
| 0.11114(51)
| 0.11114-0.11114
|
| 143Ce
| 58
| 85
| 142.912386(3)
| 33.039(6) h
| 3/2-
|
|
|
| 144Ce
| 58
| 86
| 143.913647(4)
| 284.91(5) d
| 0+
|
|
|
| 145Ce
| 58
| 87
| 144.91723(4)
| 3.01(6) min
| (3/2-)
|
|
|
| 146Ce
| 58
| 88
| 145.91876(7)
| 13.52(13) min
| 0+
|
|
|
| 147Ce
| 58
| 89
| 146.92267(3)
| 56.4(10) s
| (5/2-)
|
|
|
| 148Ce
| 58
| 90
| 147.92443(3)
| 56(1) s
| 0+
|
|
|
| 149Ce
| 58
| 91
| 148.9284(1)
| 5.3(2) s
| (3/2-)#
|
|
|
| 150Ce
| 58
| 92
| 149.93041(5)
| 4.0(6) s
| 0+
|
|
|
| 151Ce
| 58
| 93
| 150.93398(11)
| 1.02(6) s
| 3/2-#
|
|
|
| 152Ce
| 58
| 94
| 151.93654(21)#
| 1.4(2) s
| 0+
|
|
|
| 153Ce
| 58
| 95
| 152.94058(43)#
| 500# ms [>300 ns]
| 3/2-#
|
|
|
| 154Ce
| 58
| 96
| 153.94342(54)#
| 300# ms [>300 ns]
| 0+
|
|
|
| 155Ce
| 58
| 97
| 154.94804(64)#
| 200# ms [>300 ns]
| 5/2-#
|
|
|
| 156Ce
| 58
| 98
| 155.95126(64)#
| 150# ms
| 0+
|
|
|
| 157Ce
| 58
| 99
| 156.95634(75)#
| 50# ms
| 7/2+#
|
|
|
Notes
- Evaluated isotopic composition is for most but not all commercial samples.
- Geologically exceptional samples are known in which the isotopic composition lies outside the reported range. The uncertainty in the atomic mass may exceed the stated value for such specimens.
- 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 Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
- Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
- Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.
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