Erbium-177

Properties and data of the isotope ¹⁷⁷Er.

Content

General data

Name of the isotope:Erbium-177; Er-177Symbol:¹⁷⁷Er or 17768ErMass number A:177 (= number of nucleons)Atomic number Z:68 (= number of protons)Neutrons N:109Isotopic mass:176.95399(54) u (atomic weight of Erbium-177)Nuclide mass:176.9166899 u (calculated nuclear mass without electrons)Mass excess:-42.85804 MeVMass defect:1.52258802 u (per nucleus)Nuclear binding energy:1418.2816051 MeV (per nucleus)
8.01289042 MeV (average binding energy per nucleon)Separation energy:S_N = 4.30(64) MeV (first neutron)
S_P = 10.86(71) MeV (first proton)Half-life:3 sDecay constant λ:0.23104906018665 s^-1Specific activity α:7.905738556818 × 10⁺²⁰ Bq g^-1
21366860964.374 Ci g^-1Spin and parity:
(nuclear angular momentum)(1/2-)Year of discovery:2012

Radioactive Decay

Half-life T_½ = 3 s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁷⁷Tm	100 %	4.61(58) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 109) and isobaric (same nucleon number A = 177) with Erbium-177. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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