Terbium-172

Properties and data of the isotope ¹⁷²Tb.

Content

General data

Name of the isotope:Terbium-172; Tb-172Symbol:¹⁷²Tb or 17265TbMass number A:172 (= number of nucleons)Atomic number Z:65 (= number of protons)Neutrons N:107Isotopic mass:171.95722(54) u (atomic weight of Terbium-172)Nuclide mass:171.9215653 u (calculated nuclear mass without electrons)Mass excess:-39.84931 MeVMass defect:1.478553092 u (per nucleus)Nuclear binding energy:1377.26333388 MeV (per nucleus)
8.00734496 MeV (average binding energy per nucleon)Separation energy:S_N = 3.89(71) MeV (first neutron)Half-life:0.76(19) sDecay constant λ:0.91203576389466 s^-1Specific activity α:3.211934409048 × 10⁺²¹ Bq g^-1
86809038082.403 Ci g^-1Spin and parity:
(nuclear angular momentum)(6+)Year of discovery:2012

Radioactive Decay

Half-life T_½ = 0.76(19) s respectively 7.6 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁷²Dy	100 %	8.16(58) MeV
β^-, n	¹⁷¹Dy	?	2.27(58) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 107) and isobaric (same nucleon number A = 172) with Terbium-172. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 107	Isobar A = 172
65	¹⁷²Tb	¹⁷²Tb
66	¹⁷³Dy	¹⁷²Dy
67	¹⁷⁴Ho	¹⁷²Ho
68	¹⁷⁵Er	¹⁷²Er
69	¹⁷⁶Tm	¹⁷²Tm
70	¹⁷⁷Yb	¹⁷²Yb
71	¹⁷⁸Lu	¹⁷²Lu
72	¹⁷⁹Hf	¹⁷²Hf
73	¹⁸⁰Ta	¹⁷²Ta
74	¹⁸¹W	¹⁷²W
75	¹⁸²Re	¹⁷²Re
76	¹⁸³Os	¹⁷²Os
77	¹⁸⁴Ir	¹⁷²Ir
78	¹⁸⁵Pt	¹⁷²Pt
79	¹⁸⁶Au	¹⁷²Au
80	¹⁸⁷Hg	¹⁷²Hg
81	¹⁸⁸Tl
82	¹⁸⁹Pb
83	¹⁹⁰Bi
84	¹⁹¹Po
85	¹⁹²At
86	¹⁹³Rn