Isotopes of samarium

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Samarium (Sm)
Standard atomic mass: 150.36(2) u

[edit] 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
128Sm 62 66 127.95808(54)# 0.5# s 0+
129Sm 62 67 128.95464(54)# 550(100) ms 5/2+#
130Sm 62 68 129.94892(43)# 1# s 0+
131Sm 62 69 130.94611(32)# 1.2(2) s 5/2+#
132Sm 62 70 131.94069(32)# 4.0(3) s 0+
133Sm 62 71 132.93867(21)# 2.90(17) s (5/2+)
134Sm 62 72 133.93397(21)# 10(1) s 0+
135Sm 62 73 134.93252(17) 10.3(5) s (7/2+)
135mSm 0(300)# keV 2.4(9) s (3/2+,5/2+)
136Sm 62 74 135.928276(13) 47(2) s 0+
136mSm 2264.7(11) keV 15(1) µs (8-)
137Sm 62 75 136.92697(5) 45(1) s (9/2-)
137mSm 180(50)# keV 20# s 1/2+#
138Sm 62 76 137.923244(13) 3.1(2) min 0+
139Sm 62 77 138.922297(12) 2.57(10) min 1/2+
139mSm 457.40(22) keV 10.7(6) s 11/2-
140Sm 62 78 139.918995(13) 14.82(12) min 0+
141Sm 62 79 140.918476(9) 10.2(2) min 1/2+
141mSm 176.0(3) keV 22.6(2) min 11/2-
142Sm 62 80 141.915198(6) 72.49(5) min 0+
143Sm 62 81 142.914628(4) 8.75(8) min 3/2+
143m1Sm 753.99(16) keV 66(2) s 11/2-
143m2Sm 2793.8(13) keV 30(3) ms 23/2(-)
144Sm 62 82 143.911999(3) STABLE 0+ 0.0307(7)
144mSm 2323.60(8) keV 880(25) ns 6+
145Sm 62 83 144.913410(3) 340(3) d 7/2-
145mSm 8786.2(7) keV 990(170) ns [0.96(+19-15) µs] (49/2+)
146Sm 62 84 145.913041(4) 1.03(5)E+8 a 0+
147Sm 62 85 146.9148979(26) 106.0(11)E+12 7/2- 0.1499(18)
148Sm 62 86 147.9148227(26) 7(3)E+15 a 0+ 0.1124(10)
149Sm 62 87 148.9171847(26) STABLE [>2E+15 a] 7/2- 0.1382(7)
150Sm 62 88 149.9172755(26) STABLE 0+ 0.0738(1)
151Sm 62 89 150.9199324(26) 90(8) a 5/2-
151mSm 261.13(4) keV 1.4(1) µs (11/2)-
152Sm 62 90 151.9197324(27) STABLE 0+ 0.2675(16)
153Sm 62 91 152.9220974(27) 46.284(4) h 3/2+
153mSm 98.37(10) keV 10.6(3) ms 11/2-
154Sm 62 92 153.9222093(27) STABLE [>2.3E+18 a] 0+ 0.2275(29)
155Sm 62 93 154.9246402(28) 22.3(2) min 3/2-
156Sm 62 94 155.925528(10) 9.4(2) h 0+
156mSm 1397.55(9) keV 185(7) ns 5-
157Sm 62 95 156.92836(5) 8.03(7) min (3/2-)
158Sm 62 96 157.92999(8) 5.30(3) min 0+
159Sm 62 97 158.93321(11) 11.37(15) s 5/2-
160Sm 62 98 159.93514(21)# 9.6(3) s 0+
161Sm 62 99 160.93883(32)# 4.8(8) s 7/2+#
162Sm 62 100 161.94122(54)# 2.4(5) s 0+
163Sm 62 101 162.94536(75)# 1# s 1/2-#
164Sm 62 102 163.94828(86)# 500# ms 0+
165Sm 62 103 164.95298(97)# 200# ms 5/2-#

[edit] 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.

[edit] References


Isotopes of promethium Isotopes of samarium Isotopes of europium
Index to isotope pages