Erbium-165

Properties and data of the isotope ¹⁶⁵Er.

Content

General data

Name of the isotope:Erbium-165; Er-165Symbol:¹⁶⁵Er or 16568ErMass number A:165 (= number of nucleons)Atomic number Z:68 (= number of protons)Neutrons N:97Isotopic mass:164.9307332(10) u (atomic weight of Erbium-165)Nuclide mass:164.8934331 u (calculated nuclear mass without electrons)Mass excess:-64.52161 MeVMass defect:1.441865828 u (per nucleus)Nuclear binding energy:1343.08936759 MeV (per nucleus)
8.13993556 MeV (average binding energy per nucleon)Separation energy:S_N = 6.6500(6) MeV (first neutron)
S_P = 6.8291(15) MeV (first proton)Half-life:10.36(4) hDecay constant λ:1.858502736379 × 10^-5 s^-1Specific activity α:6.824491016495 × 10⁺¹⁶ Bq g^-1
1844457.0314853 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2-Magnetic dipole moment:μ(μ_N) = + 0.643(3)Quadrupole moment Q:+ 2.71(3) barn (100 fm²)Nuclear g-factor:g_l = 0.2572Year of discovery:1950

Radioactive Decay

Half-life T_½ = 10.36(4) h (hours) respectively 3.7296 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE	¹⁶⁵Ho	100 %	0.3774(14) MeV

Parent Nuclides

Direct parent isotope is: ¹⁶⁵Tm.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 97) and isobaric (same nucleon number A = 165) with Erbium-165. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 97	Isobar A = 165
56	¹⁵³Ba
57	¹⁵⁴La
58	¹⁵⁵Ce
59	¹⁵⁶Pr
60	¹⁵⁷Nd
61	¹⁵⁸Pm
62	¹⁵⁹Sm	¹⁶⁵Sm
63	¹⁶⁰Eu	¹⁶⁵Eu
64	¹⁶¹Gd	¹⁶⁵Gd
65	¹⁶²Tb	¹⁶⁵Tb
66	¹⁶³Dy	¹⁶⁵Dy
67	¹⁶⁴Ho	¹⁶⁵Ho
68	¹⁶⁵Er	¹⁶⁵Er
69	¹⁶⁶Tm	¹⁶⁵Tm
70	¹⁶⁷Yb	¹⁶⁵Yb
71	¹⁶⁸Lu	¹⁶⁵Lu
72	¹⁶⁹Hf	¹⁶⁵Hf
73	¹⁷⁰Ta	¹⁶⁵Ta
74	¹⁷¹W	¹⁶⁵W
75	¹⁷²Re	¹⁶⁵Re
76	¹⁷³Os	¹⁶⁵Os
77	¹⁷⁴Ir	¹⁶⁵Ir
78	¹⁷⁵Pt
79	¹⁷⁶Au
80	¹⁷⁷Hg
81	¹⁷⁸Tl
82	¹⁷⁹Pb