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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).

Additional recommended knowledge

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.


Isotopes of cerium Isotopes of praseodymium Isotopes of neodymium
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_praseodymium". A list of authors is available in Wikipedia.
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