Isotopes of lanthanum
Naturally occurring lanthanum (La) is composed of one stable (139La) and one radioactive (138La) isotope, with the stable isotope, 139La, being the most abundant (99.91% natural abundance). There are 38 radioisotopes that have been characterized, with the most stable being 138La, with a half-life of 102×109 years; 137La, with a half-life of 60,000 years and 140La, with a half-life of 1.6781 days. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these have half-lives that are less than 1 minute. This element also has 12 nuclear isomers, the longest-lived of which is 132mLa, with a half-life of 24.3 minutes.
The isotopes of lanthanum range in atomic weight from 116.95 u (117La) to 154.96 u (155La).
Relative atomic mass: 138.90547(7).
Table
nuclide symbol |
Z(p) | N(n) | isotopic mass (u) |
half-life[n 1] | decay mode(s)[1][n 2] |
daughter isotope(s)[n 3] |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
---|---|---|---|---|---|---|---|---|---|
excitation energy | |||||||||
117La | 57 | 60 | 116.95007(43)# | 23.5(26) ms | β+ | 117Ba | (3/2+,3/2−) | ||
p | 116Ba | ||||||||
117mLa | 151(12) keV | 10(5) ms | (9/2+) | ||||||
118La | 57 | 61 | 117.94673(32)# | 200# ms | β+ | 118Ba | |||
119La | 57 | 62 | 118.94099(43)# | 1# s | β+ | 119Ba | 11/2−# | ||
120La | 57 | 63 | 119.93807(54)# | 2.8(2) s | β+ | 120Ba | |||
β+, p | 119Cs | ||||||||
121La | 57 | 64 | 120.93301(54)# | 5.3(2) s | β+ | 121Ba | 11/2−# | ||
β+, p | 120Cs | ||||||||
122La | 57 | 65 | 121.93071(32)# | 8.6(5) s | β+ | 122Ba | |||
β+, p | 121Cs | ||||||||
123La | 57 | 66 | 122.92624(21)# | 17(3) s | β+ | 123Ba | 11/2−# | ||
124La | 57 | 67 | 123.92457(6) | 29.21(17) s | β+ | 124Ba | (7−,8−) | ||
124mLa | 100(100)# keV | 21(4) s | low(+#) | ||||||
125La | 57 | 68 | 124.920816(28) | 64.8(12) s | β+ | 125Ba | (11/2−) | ||
125mLa | 107.0(10) keV | 390(40) ms | (3/2+) | ||||||
126La | 57 | 69 | 125.91951(10) | 54(2) s | β+ | 126Ba | (5)(+#) | ||
126mLa | 210(410) keV | 20(20) s | (0−,1−,2−) | ||||||
127La | 57 | 70 | 126.916375(28) | 5.1(1) min | β+ | 127Ba | (11/2−) | ||
127mLa | 14.8(12) keV | 3.7(4) min | β+ | 127Ba | (3/2+) | ||||
IT | 127La | ||||||||
128La | 57 | 71 | 127.91559(6) | 5.18(14) min | β+ | 128Ba | (5+) | ||
128mLa | 100(100)# keV | <1.4 min | IT | 128La | (1+,2−) | ||||
129La | 57 | 72 | 128.912693(22) | 11.6(2) min | β+ | 129Ba | 3/2+ | ||
129mLa | 172.1(4) keV | 560(50) ms | IT | 129La | 11/2− | ||||
130La | 57 | 73 | 129.912369(28) | 8.7(1) min | β+ | 130Ba | 3(+) | ||
131La | 57 | 74 | 130.91007(3) | 59(2) min | β+ | 131Ba | 3/2+ | ||
131mLa | 304.52(24) keV | 170(10) µs | 11/2− | ||||||
132La | 57 | 75 | 131.91010(4) | 4.8(2) h | β+ | 132Ba | 2− | ||
132mLa | 188.18(11) keV | 24.3(5) min | IT (76%) | 132La | 6− | ||||
β+ (24%) | 132Ba | ||||||||
133La | 57 | 76 | 132.90822(3) | 3.912(8) h | β+ | 133Ba | 5/2+ | ||
134La | 57 | 77 | 133.908514(21) | 6.45(16) min | β+ | 134Ba | 1+ | ||
135La | 57 | 78 | 134.906977(11) | 19.5(2) h | β+ | 135Ba | 5/2+ | ||
136La | 57 | 79 | 135.90764(6) | 9.87(3) min | β+ | 136Ba | 1+ | ||
136mLa | 255(9) keV | 114(3) ms | IT | 136La | (8)(−#) | ||||
137La | 57 | 80 | 136.906494(14) | 6(2)×104 y | EC | 137Ba | 7/2+ | ||
138La[n 4] | 57 | 81 | 137.907112(4) | 1.02(1)×1011 y | β+ (66.4%) | 138Ba | 5+ | 9.0(1)×10−4 | |
β− (33.6%) | 138Ce | ||||||||
138mLa | 72.57(3) keV | 116(5) ns | (3)+ | ||||||
139La[n 5] | 57 | 82 | 138.9063533(26) | Stable[n 6] | 7/2+ | 0.99910(1) | |||
140La[n 5] | 57 | 83 | 139.9094776(26) | 1.6781(3) d | β− | 140Ce | 3− | ||
141La | 57 | 84 | 140.910962(5) | 3.92(3) h | β− | 141Ce | (7/2+) | ||
142La | 57 | 85 | 141.914079(6) | 91.1(5) min | β− | 142Ce | 2− | ||
143La | 57 | 86 | 142.916063(17) | 14.2(1) min | β− | 143Ce | (7/2)+ | ||
144La | 57 | 87 | 143.91960(5) | 40.8(4) s | β− | 144Ce | (3−) | ||
145La | 57 | 88 | 144.92165(10) | 24.8(20) s | β− | 145Ce | (5/2+) | ||
146La | 57 | 89 | 145.92579(8) | 6.27(10) s | β− (99.99%) | 146Ce | 2− | ||
β−, n (.007%) | 145Ce | ||||||||
146mLa | 130(130) keV | 10.0(1) s | β− | 146Ce | (6−) | ||||
147La | 57 | 90 | 146.92824(5) | 4.015(8) s | β− (99.96%) | 147Ce | (5/2+) | ||
β−, n (.04%) | 146Ce | ||||||||
148La | 57 | 91 | 147.93223(6) | 1.26(8) s | β− (99.85%) | 148Ce | (2−) | ||
β−, n (.15%) | 147Ce | ||||||||
149La | 57 | 92 | 148.93473(34)# | 1.05(3) s | β− (98.6%) | 149Ce | 5/2+# | ||
β−, n (1.4%) | 148Ce | ||||||||
150La | 57 | 93 | 149.93877(43)# | 510(30) ms | β− (97.3%) | 150Ce | (3+) | ||
β−, n (2.7%) | 149Ce | ||||||||
151La | 57 | 94 | 150.94172(43)# | 300# ms [>300 ns] | β− | 151Ce | 5/2+# | ||
152La | 57 | 95 | 151.94625(43)# | 200# ms [>300 ns] | β− | 152Ce | |||
153La | 57 | 96 | 152.94962(64)# | 150# ms [>300 ns] | β− | 153Ce | 5/2+# | ||
154La | 57 | 97 | 153.95450(64)# | 100# ms | β− | 154Ce | |||
155La | 57 | 98 | 154.95835(86)# | 60# ms | β− | 155Ce | 5/2+# |
- ↑ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
- ↑ Abbreviations:
EC: Electron capture
IT: Isomeric transition - ↑ Bold for stable isotopes, bold italics for near-stable isotopes (half-life longer than the age of the universe)
- ↑ Primordial radionuclide
- 1 2 Fission product
- ↑ Theoretically capable of spontaneous fission
Notes
- 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
- ↑ "Universal Nuclide Chart". nucleonica. (registration required (help)).
- Isotope masses from:
- G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; 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; 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.
- 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. 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; 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.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. 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 978-0-8493-0485-9.
Isotopes of barium | Isotopes of lanthanum | Isotopes of cerium |
Table of nuclides |
Isotopes of the chemical elements | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 H |
2 He | ||||||||||||||||
3 Li |
4 Be |
5 B |
6 C |
7 N |
8 O |
9 F |
10 Ne | ||||||||||
11 Na |
12 Mg |
13 Al |
14 Si |
15 P |
16 S |
17 Cl |
18 Ar | ||||||||||
19 K |
20 Ca |
21 Sc |
22 Ti |
23 V |
24 Cr |
25 Mn |
26 Fe |
27 Co |
28 Ni |
29 Cu |
30 Zn |
31 Ga |
32 Ge |
33 As |
34 Se |
35 Br |
36 Kr |
37 Rb |
38 Sr |
39 Y |
40 Zr |
41 Nb |
42 Mo |
43 Tc |
44 Ru |
45 Rh |
46 Pd |
47 Ag |
48 Cd |
49 In |
50 Sn |
51 Sb |
52 Te |
53 I |
54 Xe |
55 Cs |
56 Ba |
72 Hf |
73 Ta |
74 W |
75 Re |
76 Os |
77 Ir |
78 Pt |
79 Au |
80 Hg |
81 Tl |
82 Pb |
83 Bi |
84 Po |
85 At |
86 Rn | |
87 Fr |
88 Ra |
104 Rf |
105 Db |
106 Sg |
107 Bh |
108 Hs |
109 Mt |
110 Ds |
111 Rg |
112 Cn |
113 Uut |
114 Fl |
115 Uup |
116 Lv |
117 Uus |
118 Uuo | |
57 La |
58 Ce |
59 Pr |
60 Nd |
61 Pm |
62 Sm |
63 Eu |
64 Gd |
65 Tb |
66 Dy |
67 Ho |
68 Er |
69 Tm |
70 Yb |
71 Lu | |||
89 Ac |
90 Th |
91 Pa |
92 U |
93 Np |
94 Pu |
95 Am |
96 Cm |
97 Bk |
98 Cf |
99 Es |
100 Fm |
101 Md |
102 No |
103 Lr | |||
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