Terbium-168

Properties and data of the isotope ¹⁶⁸Tb.

Content

General data

Name of the isotope:Terbium-168; Tb-168Symbol:¹⁶⁸Tb or 16865TbMass number A:168 (= number of nucleons)Atomic number Z:65 (= number of protons)Neutrons N:103Isotopic mass:167.94340(32) u (atomic weight of Terbium-168)Nuclide mass:167.9077453 u (calculated nuclear mass without electrons)Mass excess:-52.72256 MeVMass defect:1.457713428 u (per nucleus)Nuclear binding energy:1357.8513119 MeV (per nucleus)
8.08244829 MeV (average binding energy per nucleon)Separation energy:S_N = 4.87(36) MeV (first neutron)
S_P = 9.20(42) MeV (first proton)Half-life:8.2(13) sDecay constant λ:0.084530143970725 s^-1Specific activity α:3.048218167080 × 10⁺²⁰ Bq g^-1
8238427478.5959 Ci g^-1Spin and parity:
(nuclear angular momentum)(4-)Year of discovery:1999

Radioactive Decay

Half-life T_½ = 8.2(13) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁶⁸Dy	100 %	5.84(33) 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 = 168) with Terbium-168. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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