Thulium-177

Properties and data of the isotope ¹⁷⁷Tm.

Contents

General data

Name of the isotope:Thulium-177; Tm-177Symbol:¹⁷⁷Tm or 17769TmMass number A:177 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:108Isotopic mass:176.94904(32) u (atomic weight of Thulium-177)Nuclide mass:176.9111914 u (calculated nuclear mass without electrons)Mass excess:-47.46893 MeVMass defect:1.526698136 u (per nucleus)Nuclear binding energy:1422.1101535 MeV (per nucleus)
8.03452064 MeV (average binding energy per nucleon)Separation energy:S_N = 6.17(31) MeV (first neutron)
S_P = 8.13(50) MeV (first proton)Half-life:95(7) sDecay constant λ:0.0072962861111573 s^-1Specific activity α:2.496549017942 × 10⁺¹⁹ Bq g^-1
674742977.82232 Ci g^-1Spin and parity:
(nuclear angular momentum)(1/2+)Year of discovery:1989

Radioactive Decay

Half-life T_½ = 95(7) s respectively 9.5 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁷⁷Yb	≤ 100 %	3.52(30) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 108) and isobaric (same nucleon number A = 177) with Thulium-177. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 108	Isobar A = 177
66	¹⁷⁴Dy
67	¹⁷⁵Ho
68	¹⁷⁶Er	¹⁷⁷Er
69	¹⁷⁷Tm	¹⁷⁷Tm
70	¹⁷⁸Yb	¹⁷⁷Yb
71	¹⁷⁹Lu	¹⁷⁷Lu
72	¹⁸⁰Hf	¹⁷⁷Hf
73	¹⁸¹Ta	¹⁷⁷Ta
74	¹⁸²W	¹⁷⁷W
75	¹⁸³Re	¹⁷⁷Re
76	¹⁸⁴Os	¹⁷⁷Os
77	¹⁸⁵Ir	¹⁷⁷Ir
78	¹⁸⁶Pt	¹⁷⁷Pt
79	¹⁸⁷Au	¹⁷⁷Au
80	¹⁸⁸Hg	¹⁷⁷Hg
81	¹⁸⁹Tl	¹⁷⁷Tl
82	¹⁹⁰Pb
83	¹⁹¹Bi
84	¹⁹²Po
85	¹⁹³At
86	¹⁹⁴Rn