Naturally occurring
cerium
Cerium is a chemical element; it has Chemical symbol, symbol Ce and atomic number 58. It is a hardness, soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it ...
(
58Ce) is composed of 4 stable
isotope
Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...
s:
136Ce,
138Ce,
140Ce, and
142Ce, with
140Ce being the most abundant (88.48%
natural abundance
In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the ato ...
) and the only one theoretically stable;
136Ce,
138Ce, and
142Ce are predicted to undergo
double beta decay
In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa, inside an atomic nucleus. As in single beta decay, this process allows the atom to move cl ...
but this process has never been observed. There are 35
radioisotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...
s that have been characterized, with the most stable being
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
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...
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 10
meta state
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state levels (higher energy levels). "Metastable" describes nuclei whose excited states have half-lives of 10−9 s ...
s.
The isotopes of cerium range in
atomic weight
Relative atomic mass (symbol: ''A''; sometimes abbreviated RAM or r.a.m.), also known by the deprecated synonym atomic weight, is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a giv ...
from 119
u (
119Ce) to 157 u (
157Ce).
List of isotopes
, -id=Cerium-121
, rowspan=2,
121Ce
, rowspan=2 style="text-align:right" , 58
, rowspan=2 style="text-align:right" , 63
, rowspan=2, 120.94344(43)#
, rowspan=2, 1.1(1) s
,
β+ (99%)
,
121La
, rowspan=2, 5/2(+#)
, rowspan=2,
, rowspan=2,
, -
, β
+,
p (1%)
,
120Ba
, -id=Cerium-122
,
122Ce
, style="text-align:right" , 58
, style="text-align:right" , 64
, 121.93787(43)#
, 2# s
, β
+
,
122La
, 0+
,
,
, -id=Cerium-123
, rowspan=2,
123Ce
, rowspan=2 style="text-align:right" , 58
, rowspan=2 style="text-align:right" , 65
, rowspan=2, 122.93528(32)#
, rowspan=2, 3.8(2) s
, β
+ (?%)
,
123La
, rowspan=2, (5/2)(+#)
, rowspan=2,
, rowspan=2,
, -
, β
+, p (?%)
,
122Ba
, -id=Cerium-124
,
124Ce
, style="text-align:right" , 58
, style="text-align:right" , 66
, 123.93031(32)#
, 9.1(12) s
, β
+
,
124La
, 0+
,
,
, -id=Cerium-125
, rowspan=2,
125Ce
, rowspan=2 style="text-align:right" , 58
, rowspan=2 style="text-align:right" , 67
, rowspan=2, 124.92844(21)#
, rowspan=2, 9.7(3) s
, β
+ (?%)
,
125La
, rowspan=2, (7/2−)
, rowspan=2,
, rowspan=2,
, -
, β
+, p (?%)
,
124Ba
, -id=Cerium-125m
, style="text-indent:1em" ,
125mCe
, colspan="3" style="text-indent:2em" , 93.6(4) keV
, 13(10) s
,
IT
,
125Ce
, (1/2+)
,
,
, -id=Cerium-126
,
126Ce
, style="text-align:right" , 58
, style="text-align:right" , 68
, 125.923971(30)
, 51.0(3) s
, β
+
,
126La
, 0+
,
,
, -id=Cerium-127
,
127Ce
, style="text-align:right" , 58
, style="text-align:right" , 69
, 126.922727(31)
, 34(2) s
, β
+
,
127La
, (1/2+)
,
,
, -id=Cerium-127m1
, style="text-indent:1em" ,
127m1Ce
, colspan="3" style="text-indent:2em" , 7.3(11) keV
, 28.6(7) s
, β
+
,
127La
, (5/2+)
,
,
, -id=Cerium-127m2
, style="text-indent:1em" ,
127m2Ce
, colspan="3" style="text-indent:2em" , 36.9(11) keV
, >10 μs
, IT
,
127Ce
, (7/2−)
,
,
, -id=Cerium-128
,
128Ce
, style="text-align:right" , 58
, style="text-align:right" , 70
, 127.918911(30)
, 3.93(2) min
, β
+
,
128La
, 0+
,
,
, -id=Cerium-129
,
129Ce
, style="text-align:right" , 58
, style="text-align:right" , 71
, 128.918102(30)
, 3.5(3) min
, β
+
,
129La
, (5/2+)
,
,
, -id=Cerium-130
,
130Ce
, style="text-align:right" , 58
, style="text-align:right" , 72
, 129.914736(30)
, 22.9(5) min
, β
+
,
130La
, 0+
,
,
, -id=Cerium-130m
, style="text-indent:1em" ,
130mCe
, colspan="3" style="text-indent:2em" , 2453.6(3) keV
, 100(8) ns
, IT
,
130Ce
, 7−
,
,
, -id=Cerium-131
,
131Ce
, style="text-align:right" , 58
, style="text-align:right" , 73
, 130.914429(35)
, 10.3(3) min
, β
+
,
131La
, 7/2+
,
,
, -id=Cerium-131m
, style="text-indent:1em" ,
131mCe
, colspan="3" style="text-indent:2em" , 63.09(9) keV
, 5.4(4) min
, β
+
,
131La
, (1/2+)
,
,
, -id=Cerium-132
,
132Ce
, style="text-align:right" , 58
, style="text-align:right" , 74
, 131.911466(22)
, 3.51(11) h
, β
+
,
132La
, 0+
,
,
, -id=Cerium-132m
, style="text-indent:1em" ,
132mCe
, colspan="3" style="text-indent:2em" , 2341.15(21) keV
, 9.4(3) ms
, IT
,
132Ce
, 8−
,
,
, -id=Cerium-133
,
133Ce
, style="text-align:right" , 58
, style="text-align:right" , 75
, 132.911520(18)
, 97(4) min
, β
+
,
133La
, 1/2+
,
,
, -id=Cerium-133m
, style="text-indent:1em" ,
133mCe
, colspan="3" style="text-indent:2em" , 37.2(7) keV
, 5.1(3) h
, β
+
,
133La
, 9/2−
,
,
, -id=Cerium-134
,
134Ce
, style="text-align:right" , 58
, style="text-align:right" , 76
, 133.908928(22)
, 3.16(4) d
,
EC
,
134La
, 0+
,
,
, -id=Cerium-134m
, style="text-indent:1em" ,
134mCe
, colspan="3" style="text-indent:2em" , 3208.6(4) keV
, 308(5) ns
, IT
,
134Ce
, 10+
,
,
, -id=Cerium-135
,
135Ce
, style="text-align:right" , 58
, style="text-align:right" , 77
, 134.909161(11)
, 17.7(3) h
, β
+
,
135La
, 1/2+
,
,
, -id=Cerium-135m
, style="text-indent:1em" ,
135mCe
, colspan="3" style="text-indent:2em" , 445.81(21) keV
, 20(1) s
, IT
,
135Ce
, (11/2−)
,
,
, -id=Cerium-136
,
136Ce
, style="text-align:right" , 58
, style="text-align:right" , 78
, 135.90712926(35)
, colspan=3 align=center,
Observationally Stable
Stable nuclides are isotopes of a chemical element whose nucleons are in a configuration that does not permit them the surplus energy required to produce a radioactive emission. The nuclei of such isotopes are not radioactive and unlike radionuc ...
[Theorized to undergo β+β+ decay to 136Ba with a ]half-life Half-life is a mathematical and scientific description of exponential or gradual decay.
Half-life, half life or halflife may also refer to:
Film
* Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang
* ''Half Life: ...
over 3.2×1016 years
, 0+
, 0.00186(2)
,
, -id=Cerium-136m
, style="text-indent:1em" ,
136mCe
, colspan="3" style="text-indent:2em" , 3095.0(6) keV
, 1.96(9) μs
, IT
,
136Ce
, 10+
,
,
, -id=Cerium-137
,
137Ce
, style="text-align:right" , 58
, style="text-align:right" , 79
, 136.90776242(39)
, 9.0(3) h
, β
+
,
137La
, 3/2+
,
,
, -id=Cerium-137m
, rowspan=2 style="text-indent:1em" ,
137mCe
, rowspan=2 colspan="3" style="text-indent:2em" , 254.29(5) keV
, rowspan=2, 34.4(3) h
, IT (99.21%)
,
137Ce
, rowspan=2, 11/2−
, rowspan=2,
, rowspan=2,
, -
, β
+ (0.79%)
,
137La
, -id=Cerium-138
,
138Ce
, style="text-align:right" , 58
, style="text-align:right" , 80
, 137.90599418(54)
, colspan=3 align=center, Observationally Stable
[Theorized to undergo β+β+ decay to 138Ba with a half-life over 4.4×1016 years]
, 0+
, 0.00251(2)
,
, -id=Cerium-138m
, style="text-indent:1em" ,
138mCe
, colspan="3" style="text-indent:2em" , 2129.28(12) keV
, 8.73(20) ms
, IT
,
138Ce
, 7-
,
,
, -id=Cerium-139
,
139Ce
, style="text-align:right" , 58
, style="text-align:right" , 81
, 138.9066470(22)
, 137.642(20) d
, EC
,
139La
, 3/2+
,
,
, -id=Cerium-139m
, style="text-indent:1em" ,
139mCe
, colspan="3" style="text-indent:2em" , 754.24(8) keV
, 57.58(32) s
, IT
,
139Ce
, 11/2−
,
,
, -id=Cerium-140
,
140Ce
Fission product
Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the releas ...
, style="text-align:right" , 58
, style="text-align:right" , 82
, 139.9054484(14)
, colspan=3 align=center, Stable
, 0+
, 0.88449(51)
,
, -id=Cerium-140m
, style="text-indent:1em" ,
140mCe
, colspan="3" style="text-indent:2em" , 2107.854(24) keV
, 7.3(15) μs
, IT
,
140Ce
, 6+
,
,
, -id=Cerium-141
,
141Ce
, style="text-align:right" , 58
, style="text-align:right" , 83
, 140.9082860(14)
, 32.505(10) d
, β
−
,
141Pr
, 7/2−
,
,
, -id=Cerium-142
,
142Ce
, style="text-align:right" , 58
, style="text-align:right" , 84
, 141.9092502(26)
, colspan=3 align=center, Observationally Stable
[Theorized to undergo β−β− decay to 142Nd or α decay to 138Ba with a half-life over 2.9×1018 years]
, 0+
, 0.11114(51)
,
, -id=Cerium-143
,
143Ce
, style="text-align:right" , 58
, style="text-align:right" , 85
, 142.9123920(26)
, 33.039(6) h
, β
−
,
143Pr
, 3/2−
,
,
, -id=Cerium-144
,
144Ce
, style="text-align:right" , 58
, style="text-align:right" , 86
, 143.9136528(30)
, 284.886(25) d
, β
−
,
144Pr
, 0+
,
,
, -id=Cerium-145
,
145Ce
, style="text-align:right" , 58
, style="text-align:right" , 87
, 144.917265(36)
, 3.01(6) min
, β
−
,
145Pr
, 5/2−#
,
,
, -id=Cerium-146
,
146Ce
, style="text-align:right" , 58
, style="text-align:right" , 88
, 145.918812(16)
, 13.49(16) min
, β
−
,
146Pr
, 0+
,
,
, -id=Cerium-147
,
147Ce
, style="text-align:right" , 58
, style="text-align:right" , 89
, 146.9226899(92)
, 56.4(10) s
, β
−
,
147Pr
, (5/2−)
,
,
, -id=Cerium-148
,
148Ce
, style="text-align:right" , 58
, style="text-align:right" , 90
, 147.924424(12)
, 56.8(3) s
, β
−
,
148Pr
, 0+
,
,
, -id=Cerium-149
,
149Ce
, style="text-align:right" , 58
, style="text-align:right" , 91
, 148.928427(11)
, 4.94(4) s
, β
−
,
149Pr
, 3/2−#
,
,
, -id=Cerium-150
,
150Ce
, style="text-align:right" , 58
, style="text-align:right" , 92
, 149.930384(13)
, 6.05(7) s
, β
−
,
150Pr
, 0+
,
,
, -id=Cerium-151
,
151Ce
, style="text-align:right" , 58
, style="text-align:right" , 93
, 150.934272(19)
, 1.76(6) s
, β
−
,
151Pr
, (3/2−)
,
,
, -id=Cerium-152
,
152Ce
, style="text-align:right" , 58
, style="text-align:right" , 94
, 151.93668(22)#
, 1.42(2) s
, β
−
,
152Pr
, 0+
,
,
, -id=Cerium-153
,
153Ce
, style="text-align:right" , 58
, style="text-align:right" , 95
, 152.94105(22)#
, 865(25) ms
, β
−
,
153Pr
, 3/2−#
,
,
, -id=Cerium-154
,
154Ce
, style="text-align:right" , 58
, style="text-align:right" , 96
, 153.94394(22)#
, 722(14) ms
, β
−
,
154Pr
, 0+
,
,
, -id=Cerium-155
,
155Ce
, style="text-align:right" , 58
, style="text-align:right" , 97
, 154.94871(32)#
, 313(7) ms
, β
−
,
155Pr
, 5/2−#
,
,
, -id=Cerium-156
,
156Ce
, style="text-align:right" , 58
, style="text-align:right" , 98
, 155.95188(32)#
, 233(9) ms
, β
−
,
156Pr
, 0+
,
,
, -id=Cerium-157
,
157Ce
, style="text-align:right" , 58
, style="text-align:right" , 99
, 156.95713(43)#
, 175(41) ms
, β
−
,
157Pr
, 7/2+#
,
,
, -id=Cerium-158
,
158Ce
, style="text-align:right" , 58
, style="text-align:right" , 100
, 157.96077(43)#
, 99(93) ms
, β
−
,
158Pr
, 0+
,
,
See also
Daughter products other than cerium
*
Isotopes of praseodymium
*
Isotopes of lanthanum
*
Isotopes of barium
Naturally occurring barium (56Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in roc ...
References
* Isotope masses from:
**
* Isotopic compositions and standard atomic masses from:
**
**
* Half-life, spin, and isomer data selected from the following sources.
**
**
**
{{Authority control
Cerium
Cerium
Cerium is a chemical element; it has Chemical symbol, symbol Ce and atomic number 58. It is a hardness, soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it ...