Samarium-165

Properties and data of the isotope ¹⁶⁵Sm.

Content

General data

Name of the isotope:Samarium-165; Sm-165Symbol:¹⁶⁵Sm or 16562SmMass number A:165 (= number of nucleons)Atomic number Z:62 (= number of protons)Neutrons N:103Isotopic mass:164.95297(43) u (atomic weight of Samarium-165)Nuclide mass:164.9189607 u (calculated nuclear mass without electrons)Mass excess:-43.80816 MeVMass defect:1.424668332 u (per nucleus)Nuclear binding energy:1327.07000325 MeV (per nucleus)
8.0428485 MeV (average binding energy per nucleon)Half-life:0.98(21) sDecay constant λ:0.7072930413877 s^-1Specific activity α:2.597206295420 × 10⁺²¹ Bq g^-1
70194764741.097 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2-)Year of discovery:2012

Radioactive Decay

Half-life T_½ = 0.98(21) s respectively 9.8 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁶⁵Eu	100 %	6.92(42) MeV
β^-, n	¹⁶⁴Eu	?	1.50(42) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 103) and isobaric (same nucleon number A = 165) with Samarium-165. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 103	Isobar A = 165
60	¹⁶³Nd
62	¹⁶⁵Sm	¹⁶⁵Sm
63	¹⁶⁶Eu	¹⁶⁵Eu
64	¹⁶⁷Gd	¹⁶⁵Gd
65	¹⁶⁸Tb	¹⁶⁵Tb
66	¹⁶⁹Dy	¹⁶⁵Dy
67	¹⁷⁰Ho	¹⁶⁵Ho
68	¹⁷¹Er	¹⁶⁵Er
69	¹⁷²Tm	¹⁶⁵Tm
70	¹⁷³Yb	¹⁶⁵Yb
71	¹⁷⁴Lu	¹⁶⁵Lu
72	¹⁷⁵Hf	¹⁶⁵Hf
73	¹⁷⁶Ta	¹⁶⁵Ta
74	¹⁷⁷W	¹⁶⁵W
75	¹⁷⁸Re	¹⁶⁵Re
76	¹⁷⁹Os	¹⁶⁵Os
77	¹⁸⁰Ir	¹⁶⁵Ir
78	¹⁸¹Pt
79	¹⁸²Au
80	¹⁸³Hg
81	¹⁸⁴Tl
82	¹⁸⁵Pb
83	¹⁸⁶Bi
84	¹⁸⁷Po