Hafnium-181

Properties and data of the isotope ¹⁸¹Hf.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

See also: List of individual Hafnium isotopes (and general data sources).

General data

Name of the isotope:Hafnium-181; Hf-181Symbol:¹⁸¹Hf or 18172HfMass number A:181 (= number of nucleons)Atomic number Z:72 (= number of protons)Neutrons N:109Isotopic mass:180.9491110(15) u (atomic weight of Hafnium-181)Nuclide mass:180.909617 u (calculated nuclear mass without electrons)Mass excess:-47.4028 MeVMass defect:1.558767148 u (per nucleus)Nuclear binding energy:1451.98224576 MeV (per nucleus)
8.02200136 MeV (average binding energy per nucleon)Separation energy:S_N = 5.69480(7) MeV (first neutron)
S_P = 8.02(7) MeV (first proton)Half-life:42.39 dDecay constant λ:1.892554095785 × 10^-7 s^-1Specific activity α:6.331792972151 × 10⁺¹⁴ Bq g^-1
17112.953978788 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2-Year of discovery:1935

Radioactive Decay

Half-life T_½ = 42.39 d respectively 3.662496 × 10⁶ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁸¹Ta	100 %	1.0355(18) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸¹Lu.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 109) and isobaric (same nucleon number A = 181) with Hafnium-181. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 109	Isobar A = 181
68	¹⁷⁷Er
69	¹⁷⁸Tm
70	¹⁷⁹Yb	¹⁸¹Yb
71	¹⁸⁰Lu	¹⁸¹Lu
72	¹⁸¹Hf	¹⁸¹Hf
73	¹⁸²Ta	¹⁸¹Ta
74	¹⁸³W	¹⁸¹W
75	¹⁸⁴Re	¹⁸¹Re
76	¹⁸⁵Os	¹⁸¹Os
77	¹⁸⁶Ir	¹⁸¹Ir
78	¹⁸⁷Pt	¹⁸¹Pt
79	¹⁸⁸Au	¹⁸¹Au
80	¹⁸⁹Hg	¹⁸¹Hg
81	¹⁹⁰Tl	¹⁸¹Tl
82	¹⁹¹Pb	¹⁸¹Pb
83	¹⁹²Bi
84	¹⁹³Po
85	¹⁹⁴At
86	¹⁹⁵Rn