Thulium-165

Properties and data of the isotope ¹⁶⁵Tm.

Contents

General data

Name of the isotope:Thulium-165; Tm-165Symbol:¹⁶⁵Tm or 16569TmMass number A:165 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:96Isotopic mass:164.9324423(18) u (atomic weight of Thulium-165)Nuclide mass:164.8945937 u (calculated nuclear mass without electrons)Mass excess:-62.92959 MeVMass defect:1.439316844 u (per nucleus)Nuclear binding energy:1340.71500428 MeV (per nucleus)
8.12554548 MeV (average binding energy per nucleon)Separation energy:S_N = 9.097(24) MeV (first neutron)
S_P = 4.2757(15) MeV (first proton)Half-life:30.06(3) hDecay constant λ:6.405219011605 × 10^-6 s^-1Specific activity α:2.352020190648 × 10⁺¹⁶ Bq g^-1
635681.1326077 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2+Magnetic dipole moment:μ(μ_N) = - 0.139(2)Nuclear g-factor:g_l = -0.278Charge radius:5.2004(38) femtometer fmYear of discovery:1953

Radioactive Decay

Half-life T_½ = 30.06(3) h (hours) respectively 1.08216 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁶⁵Er	100 %	1.5920(19) MeV

Parent Nuclides

Direct parent isotope is: ¹⁶⁵Yb.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 96) and isobaric (same nucleon number A = 165) with Thulium-165. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 96	Isobar A = 165
55	¹⁵¹Cs
56	¹⁵²Ba
57	¹⁵³La
58	¹⁵⁴Ce
59	¹⁵⁵Pr
60	¹⁵⁶Nd
61	¹⁵⁷Pm
62	¹⁵⁸Sm	¹⁶⁵Sm
63	¹⁵⁹Eu	¹⁶⁵Eu
64	¹⁶⁰Gd	¹⁶⁵Gd
65	¹⁶¹Tb	¹⁶⁵Tb
66	¹⁶²Dy	¹⁶⁵Dy
67	¹⁶³Ho	¹⁶⁵Ho
68	¹⁶⁴Er	¹⁶⁵Er
69	¹⁶⁵Tm	¹⁶⁵Tm
70	¹⁶⁶Yb	¹⁶⁵Yb
71	¹⁶⁷Lu	¹⁶⁵Lu
72	¹⁶⁸Hf	¹⁶⁵Hf
73	¹⁶⁹Ta	¹⁶⁵Ta
74	¹⁷⁰W	¹⁶⁵W
75	¹⁷¹Re	¹⁶⁵Re
76	¹⁷²Os	¹⁶⁵Os
77	¹⁷³Ir	¹⁶⁵Ir
78	¹⁷⁴Pt
79	¹⁷⁵Au
80	¹⁷⁶Hg
81	¹⁷⁷Tl
82	¹⁷⁸Pb