Erbium-171

Properties and data of the isotope ¹⁷¹Er.

Content

General data

Name of the isotope:Erbium-171; Er-171Symbol:¹⁷¹Er or 17168ErMass number A:171 (= number of nucleons)Atomic number Z:68 (= number of protons)Neutrons N:103Isotopic mass:170.9380361(17) u (atomic weight of Erbium-171)Nuclide mass:170.900736 u (calculated nuclear mass without electrons)Mass excess:-57.719 MeVMass defect:1.486552424 u (per nucleus)Nuclear binding energy:1384.71466364 MeV (per nucleus)
8.09774657 MeV (average binding energy per nucleon)Separation energy:S_N = 5.6816(3) MeV (first neutron)
S_P = 8.77(5) MeV (first proton)Half-life:7.516(2) hDecay constant λ:2.561746720181 × 10^-5 s^-1Specific activity α:9.074823292009 × 10⁺¹⁶ Bq g^-1
2452654.9437864 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2-Magnetic dipole moment:μ(μ_N) = 0.659(10)Quadrupole moment Q:2.89(9) barn (100 fm²)Nuclear g-factor:g_l = 0.2636Year of discovery:1938

Radioactive Decay

Half-life T_½ = 7.516(2) h (hours) respectively 2.70576 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁷¹Tm	100 %	1.4913(13) MeV

Parent Nuclides

Direct parent isotope is: ¹⁷¹Ho.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 103) and isobaric (same nucleon number A = 171) with Erbium-171. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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