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Isotopes of promethium



36 radioisotopes of Promethium (Pm) have been characterized, with the most stable being 145Pm with a half-life of 17.7 years, 146Pm with a half-life of 5.53 years, and 147Pm with a half-life of 2.6234 years. All of the remaining radioactive isotopes have half-lives that are less than 364 days, and the majority of these have half lives that are less than 27 seconds. This element also has 11 meta states with the most stable being 148Pmm (T½ 41.29 days), 152Pmm2 (T½ 13.8 minutes) and 152Pmm (T½ 7.52 minutes).

The isotopes of promethium range in atomic weight from 127.9482600 u (128Pm) to 162.9535200 u (163Pm). The primary decay mode before the longest-lived isotope, 145Pm, is electron capture, and the primary mode after is beta minus decay. The primary decay products before 145Pm are neodymium (Nd) isotopes and the primary products after are samarium (Sm) isotopes.

Additional recommended knowledge

Contents

Stability of promethium isotopes

Beside technetium, promethium is one of the two elements with atomic number less than 83 that have only unstable isotopes, which is a rarely occurring effect of the liquid drop model and stabilities of neighbor element isotopes.


Has no stable isotopes. A standard atomic mass cannot be given.

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
126Pm 61 65 125.95752(54)# 0.5# s
127Pm 61 66 126.95163(64)# 1# s 5/2+#
128Pm 61 67 127.94842(43)# 1.0(3) s 6+#
129Pm 61 68 128.94316(43)# 3# s [>200 ns] 5/2+#
130Pm 61 69 129.94045(32)# 2.6(2) s (5+,6+,4+)
131Pm 61 70 130.93587(21)# 6.3(8) s 5/2+#
132Pm 61 71 131.93375(21)# 6.2(6) s (3+)
133Pm 61 72 132.92978(5) 15(3) s (3/2+)
133mPm 130.4(10) keV 10# s (11/2-)
134Pm 61 73 133.92835(6) 22(1) s (5+)
134mPm 0(100)# keV ~5 s (2+)
135Pm 61 74 134.92488(6) 49(3) s (5/2+,3/2+)
135mPm 50(100)# keV 40(3) s (11/2-)
136Pm 61 75 135.92357(8) 107(6) s (5-)
136mPm 130(120) keV 47(2) s (2+)
137Pm 61 76 136.920479(14) 2# min 5/2+#
137mPm 150(50) keV 2.4(1) min 11/2-
138Pm 61 77 137.919548(30) 10(2) s 1+#
138mPm 30(30) keV 3.24(5) min 5-#
139Pm 61 78 138.916804(14) 4.15(5) min (5/2)+
139mPm 188.7(3) keV 180(20) ms (11/2)-
140Pm 61 79 139.91604(4) 9.2(2) s 1+
140mPm 420(40) keV 5.95(5) min 8-
141Pm 61 80 140.913555(15) 20.90(5) min 5/2+
141m1Pm 628.40(10) keV 630(20) ns 11/2-
141m2Pm 2530.9(5) keV >2 µs
142Pm 61 81 141.912874(27) 40.5(5) s 1+
142mPm 883.17(16) keV 2.0(2) ms (8)-
143Pm 61 82 142.910933(4) 265(7) d 5/2+
144Pm 61 83 143.912591(3) 363(14) d 5-
144m1Pm 840.90(5) keV 780(200) ns (9)+
144m2Pm 8595.8(22) keV ~2.7 µs (27+)
145Pm 61 84 144.912749(3) 17.7(4) a 5/2+
146Pm 61 85 145.914696(5) 5.53(5) a 3-
147Pm 61 86 146.9151385(26) 2.6234(2) a 7/2+
148Pm 61 87 147.917475(7) 5.368(2) d 1-
148mPm 137.9(3) keV 41.29(11) d 5-,6-
149Pm 61 88 148.918334(4) 53.08(5) h 7/2+
149mPm 240.214(7) keV 35(3) µs 11/2-
150Pm 61 89 149.920984(22) 2.68(2) h (1-)
151Pm 61 90 150.921207(6) 28.40(4) h 5/2+
152Pm 61 91 151.923497(28) 4.12(8) min 1+
152m1Pm 140(90) keV 7.52(8) min 4-
152m2Pm 250(150)# keV 13.8(2) min (8)
153Pm 61 92 152.924117(12) 5.25(2) min 5/2-
154Pm 61 93 153.92646(5) 1.73(10) min (0,1)
154mPm 120(120) keV 2.68(7) min (3,4)
155Pm 61 94 154.92810(3) 41.5(2) s (5/2-)
156Pm 61 95 155.93106(4) 26.70(10) s 4-
157Pm 61 96 156.93304(12) 10.56(10) s (5/2-)
158Pm 61 97 157.93656(14) 4.8(5) s
159Pm 61 98 158.93897(21)# 1.47(15) s 5/2-#
160Pm 61 99 159.94299(32)# 2# s
161Pm 61 100 160.94586(54)# 700# ms 5/2-#
162Pm 61 101 161.95029(75)# 500# ms
163Pm 61 102 162.95368(86)# 200# 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 neodymium Isotopes of promethium Isotopes of samarium
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_promethium". A list of authors is available in Wikipedia.
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