Lutetium-166m2

Properties and data of the isotope ¹⁶⁶Lu.

Content

General data

Name of the isotope:Lutetium-166m2; Lu-166m2Symbol:¹⁶⁶Lu or 16671LuMass number A:166 (= number of nucleons)Atomic number Z:71 (= number of protons)Neutrons N:95Isotopic mass:165.93986(3) u (atomic weight of Lutetium-166m2)
Excitation energy: 43.0(4) keVNuclide mass:165.9009145 u (calculated nuclear mass without electrons)Mass excess:-56.02005 MeVMass defect:1.438884292 u (per nucleus)Nuclear binding energy:1340.31208469 MeV (per nucleus)
8.07416918 MeV (average binding energy per nucleon)Half-life:2.12(10) minDecay constant λ:0.005449270287421 s^-1Specific activity α:1.988865045740 × 10⁺¹⁹ Bq g^-1
537531093.44335 Ci g^-1Spin and parity:
(nuclear angular momentum)0-

Radioactive Decay

Half-life T_½ = 2.12(10) min (minutes) respectively 1.272 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹⁶⁶Yb	> 80 %
Iso	¹⁶⁶Lu	< 10 %

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
¹⁶⁶Lu		2.65(10) min	6-
^166m1Lu	34.37(22) keV	1.41(10) min	3(-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 95) and isobaric (same nucleon number A = 166) with Lutetium-166m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 95	Isobar A = 166
55	¹⁵⁰Cs
56	¹⁵¹Ba
57	¹⁵²La
58	¹⁵³Ce
59	¹⁵⁴Pr
60	¹⁵⁵Nd
61	¹⁵⁶Pm
62	¹⁵⁷Sm	¹⁶⁶Sm
63	¹⁵⁸Eu	¹⁶⁶Eu
64	¹⁵⁹Gd	¹⁶⁶Gd
65	¹⁶⁰Tb	¹⁶⁶Tb
66	¹⁶¹Dy	¹⁶⁶Dy
67	¹⁶²Ho	¹⁶⁶Ho
68	¹⁶³Er	¹⁶⁶Er
69	¹⁶⁴Tm	¹⁶⁶Tm
70	¹⁶⁵Yb	¹⁶⁶Yb
71	¹⁶⁶Lu	¹⁶⁶Lu
72	¹⁶⁷Hf	¹⁶⁶Hf
73	¹⁶⁸Ta	¹⁶⁶Ta
74	¹⁶⁹W	¹⁶⁶W
75	¹⁷⁰Re	¹⁶⁶Re
76	¹⁷¹Os	¹⁶⁶Os
77	¹⁷²Ir	¹⁶⁶Ir
78	¹⁷³Pt	¹⁶⁶Pt
79	¹⁷⁴Au
80	¹⁷⁵Hg
81	¹⁷⁶Tl