Isotopes of praseodymium
Naturally occurring praseodymium (Pr) is composed of one stable isotope, 141Pr. Thirty-eight radioisotopes have been characterized with the most stable being 143Pr with a half-life of 13.57 days and 142Pr with a half-life of 19.12 hours. All of the remaining radioactive isotopes have half-lives that are less than 5.985 hours and the majority of these have half-lives that are less than 33 seconds. This element also has six meta states with the most stable being 138mPr (t½ 2.12 hours), 142mPr (t½ 14.6 minutes) and 134mPr (t½ 11 minutes).
The isotopes of praseodymium range in atomic weight from 120.955 u (121Pr) to 158.955 u (159Pr). The primary decay mode before the stable isotope, 141Pr, is electron capture and the primary mode after is beta minus decay. The primary decay products before 141Pr are element 58 (cerium) isotopes and the primary products after are element 60 (neodymium) isotopes.
Standard atomic mass: 140.90765(2) 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 | |||||||
| 121Pr | 59 | 62 | 120.95536(75)# | 600(300) ms | (3/2-) | ||
| 122Pr | 59 | 63 | 121.95181(54)# | 500# ms | |||
| 123Pr | 59 | 64 | 122.94596(64)# | 800# ms | 3/2+# | ||
| 124Pr | 59 | 65 | 123.94296(64)# | 1.2(2) s | |||
| 125Pr | 59 | 66 | 124.93783(43)# | 3.3(7) s | 3/2+# | ||
| 126Pr | 59 | 67 | 125.93531(21)# | 3.12(18) s | (4,5,6) | ||
| 127Pr | 59 | 68 | 126.93083(21)# | 4.2(3) s | 3/2+# | ||
| 127mPr | 600(200)# keV | 50# ms | 11/2- | ||||
| 128Pr | 59 | 69 | 127.92879(3) | 2.84(9) s | (3+) | ||
| 129Pr | 59 | 70 | 128.92510(3) | 32(3) s | (11/2-) | ||
| 129mPr | 382.7(5) keV | 1# ms | (11/2-) | ||||
| 130Pr | 59 | 71 | 129.92359(7) | 40.0(4) s | (6,7)(+#) | ||
| 130mPr | 100(100)# keV | 10# s | 2+# | ||||
| 131Pr | 59 | 72 | 130.92026(6) | 1.50(3) min | (3/2+) | ||
| 131mPr | 152.4(2) keV | 5.7(2) s | (11/2-) | ||||
| 132Pr | 59 | 73 | 131.91926(6) | 1.49(11) min | (2+) | ||
| 132mPr | 0(100)# keV | 20# s | (5+) | ||||
| 133Pr | 59 | 74 | 132.916331(13) | 6.5(3) min | (3/2+) | ||
| 133mPr | 192.05(14) keV | 1.1(2) µs | (11/2-) | ||||
| 134Pr | 59 | 75 | 133.91571(4) | ~11 min | (5-) | ||
| 134mPr | 0(100)# keV | 17(2) min | 2- | ||||
| 135Pr | 59 | 76 | 134.913112(13) | 24(2) min | 3/2(+) | ||
| 135mPr | 358.06(6) keV | 105(10) µs | (11/2-) | ||||
| 136Pr | 59 | 77 | 135.912692(13) | 13.1(1) min | 2+ | ||
| 137Pr | 59 | 78 | 136.910705(13) | 1.28(3) h | 5/2+ | ||
| 137mPr | 561.22(23) keV | 2.66(7) µs | 11/2- | ||||
| 138Pr | 59 | 79 | 137.910755(15) | 1.45(5) min | 1+ | ||
| 138mPr | 348(23) keV | 2.12(4) h | 7- | ||||
| 139Pr | 59 | 80 | 138.908938(8) | 4.41(4) h | 5/2+ | ||
| 140Pr | 59 | 81 | 139.909076(7) | 3.39(1) min | 1+ | ||
| 140m1Pr | 127.5(3) keV | 0.35(2) µs | 5+ | ||||
| 140m2Pr | 763.3(7) keV | 3.05(20) µs | (8)- | ||||
| 141Pr | 59 | 82 | 140.9076528(26) | STABLE | 5/2+ | 1.0000 | |
| 142Pr | 59 | 83 | 141.9100448(26) | 19.12(4) h | 2- | ||
| 142mPr | 3.694(3) keV | 14.6(5) min | 5- | ||||
| 143Pr | 59 | 84 | 142.9108169(28) | 13.57(2) d | 7/2+ | ||
| 144Pr | 59 | 85 | 143.913305(4) | 17.28(5) min | 0- | ||
| 144mPr | 59.03(3) keV | 7.2(3) min | 3- | ||||
| 145Pr | 59 | 86 | 144.914512(8) | 5.984(10) h | 7/2+ | ||
| 146Pr | 59 | 87 | 145.91764(7) | 24.15(18) min | (2)- | ||
| 147Pr | 59 | 88 | 146.918996(25) | 13.4(4) min | (3/2+) | ||
| 148Pr | 59 | 89 | 147.922135(28) | 2.29(2) min | 1- | ||
| 148mPr | 50(30)# keV | 2.01(7) min | (4) | ||||
| 149Pr | 59 | 90 | 148.92372(9) | 2.26(7) min | (5/2+) | ||
| 150Pr | 59 | 91 | 149.926673(28) | 6.19(16) s | (1)- | ||
| 151Pr | 59 | 92 | 150.928319(25) | 18.90(7) s | (3/2)(-#) | ||
| 152Pr | 59 | 93 | 151.93150(13) | 3.63(12) s | 4+ | ||
| 153Pr | 59 | 94 | 152.93384(11) | 4.28(11) s | 5/2-# | ||
| 154Pr | 59 | 95 | 153.93752(16) | 2.3(1) s | (3+,2+) | ||
| 155Pr | 59 | 96 | 154.94012(32)# | 1# s [>300 ns] | 5/2-# | ||
| 156Pr | 59 | 97 | 155.94427(43)# | 500# ms [>300 ns] | |||
| 157Pr | 59 | 98 | 156.94743(43)# | 300# ms | 5/2-# | ||
| 158Pr | 59 | 99 | 157.95198(64)# | 200# ms | |||
| 159Pr | 59 | 100 | 158.95550(75)# | 100# ms | 5/2-# | ||
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 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.