Erbium-169

Properties and data of the isotope ¹⁶⁹Er.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

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

General data

Name of the isotope:Erbium-169; Er-169Symbol:¹⁶⁹Er or 16968ErMass number A:169 (= number of nucleons)Atomic number Z:68 (= number of protons)Neutrons N:101Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4852941176471 (= neutron-proton ratio)Neutron excess (N-Z):33Isotopic mass:168.9345984(3) u (atomic weight of Erbium-169)Nuclide mass:168.8972983 u (calculated nuclear mass without electrons)Mass excess:-60.9212 MeVMass defect:1.472660292 u (per nucleus)Nuclear binding energy:1371.77422604 MeV (per nucleus)
8.11700725 MeV (average binding energy per nucleon)Separation energy:S_N = 6.00325(15) MeV (first neutron)
S_P = 8.15(3) MeV (first proton)Half-life:9.392(18) dDecay constant λ:8.54188331775 × 10^-7 s^-1Specific activity α:3.061930032658 × 10⁺¹⁵ Bq g^-1
82754.865747538 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2-Magnetic dipole moment:μ(μ_N) = + 0.515(25)Nuclear g-factor:g_l = 1.03Year of discovery:1956

Radioactive Decay

Half-life T_½ = 9.392(18) d respectively 8.114688 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁶⁹Tm	100 %	0.3535(8) MeV

Parent Nuclides

Direct parent isotope is: ¹⁶⁹Ho.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 101) and isobaric (same nucleon number A = 169) with Erbium-169. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 101	Isobar A = 169
58	¹⁵⁹Ce
59	¹⁶⁰Pr
60	¹⁶¹Nd
61	¹⁶²Pm
62	¹⁶³Sm
63	¹⁶⁴Eu
64	¹⁶⁵Gd	¹⁶⁹Gd
65	¹⁶⁶Tb	¹⁶⁹Tb
66	¹⁶⁷Dy	¹⁶⁹Dy
67	¹⁶⁸Ho	¹⁶⁹Ho
68	¹⁶⁹Er	¹⁶⁹Er
69	¹⁷⁰Tm	¹⁶⁹Tm
70	¹⁷¹Yb	¹⁶⁹Yb
71	¹⁷²Lu	¹⁶⁹Lu
72	¹⁷³Hf	¹⁶⁹Hf
73	¹⁷⁴Ta	¹⁶⁹Ta
74	¹⁷⁵W	¹⁶⁹W
75	¹⁷⁶Re	¹⁶⁹Re
76	¹⁷⁷Os	¹⁶⁹Os
77	¹⁷⁸Ir	¹⁶⁹Ir
78	¹⁷⁹Pt	¹⁶⁹Pt
79	¹⁸⁰Au
80	¹⁸¹Hg
81	¹⁸²Tl
82	¹⁸³Pb
83	¹⁸⁴Bi

External data and identifiers

Adopted Levels, Gammas:NuDat 169Er

Literature and References

[1] - R. Formento-Cavaier et al.:
Very high specific activity erbium ¹⁶⁹Er production for potential receptor-targeted radiotherapy.
In: Nuclear Instruments and Methods in Physics Research Section B, (2020), DOI 10.1016/j.nimb.2019.04.022.

[2] - Zeynep Talip et al.:
Production of Mass-Separated Erbium-169 Towards the First Preclinical in vitro Investigations.
In: Frontiers in Medicine, (2021), DOI 10.3389/fmed.2021.643175.

[3] - Zeynep Talip et al.:
Determination of the gamma and X-ray emission intensities of erbium-169.
In: Applied Radiation and Isotopes, (2021), DOI 10.1016/j.apradiso.2021.109823.