Erbium-173

Properties and data of the isotope ¹⁷³Er.

Content

General data

Name of the isotope:Erbium-173; Er-173Symbol:¹⁷³Er or 17368ErMass number A:173 (= number of nucleons)Atomic number Z:68 (= number of protons)Neutrons N:105Isotopic mass:172.94240(21) u (atomic weight of Erbium-173)Nuclide mass:172.9050999 u (calculated nuclear mass without electrons)Mass excess:-53.65405 MeVMass defect:1.499518356 u (per nucleus)Nuclear binding energy:1396.7923515 MeV (per nucleus)
8.07394423 MeV (average binding energy per nucleon)Separation energy:S_N = 5.24(20) MeV (first neutron)
S_P = 9.46(28) MeV (first proton)Half-life:1.4(1) minDecay constant λ:0.0082517521495232 s^-1Specific activity α:2.889140336378 × 10⁺¹⁹ Bq g^-1
780848739.56181 Ci g^-1Spin and parity:
(nuclear angular momentum)(7/2-)Year of discovery:1972

Radioactive Decay

Half-life T_½ = 1.4(1) min (minutes) respectively 8.4 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁷³Tm	100 %	2.6(2) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 105) and isobaric (same nucleon number A = 173) with Erbium-173. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 105	Isobar A = 173
63	¹⁶⁸Eu
64	¹⁶⁹Gd
65	¹⁷⁰Tb
66	¹⁷¹Dy	¹⁷³Dy
67	¹⁷²Ho	¹⁷³Ho
68	¹⁷³Er	¹⁷³Er
69	¹⁷⁴Tm	¹⁷³Tm
70	¹⁷⁵Yb	¹⁷³Yb
71	¹⁷⁶Lu	¹⁷³Lu
72	¹⁷⁷Hf	¹⁷³Hf
73	¹⁷⁸Ta	¹⁷³Ta
74	¹⁷⁹W	¹⁷³W
75	¹⁸⁰Re	¹⁷³Re
76	¹⁸¹Os	¹⁷³Os
77	¹⁸²Ir	¹⁷³Ir
78	¹⁸³Pt	¹⁷³Pt
79	¹⁸⁴Au	¹⁷³Au
80	¹⁸⁵Hg	¹⁷³Hg
81	¹⁸⁶Tl
82	¹⁸⁷Pb
83	¹⁸⁸Bi
84	¹⁸⁹Po
85	¹⁹⁰At