Erbium-154

Properties and data of the isotope ¹⁵⁴Er.

Content

General data

Name of the isotope:Erbium-154; Er-154Symbol:¹⁵⁴Er or 15468ErMass number A:154 (= number of nucleons)Atomic number Z:68 (= number of protons)Neutrons N:86Isotopic mass:153.932791(5) u (atomic weight of Erbium-154)Nuclide mass:153.8954909 u (calculated nuclear mass without electrons)Mass excess:-62.60478 MeVMass defect:1.344493952 u (per nucleus)Nuclear binding energy:1252.38804932 MeV (per nucleus)
8.13238993 MeV (average binding energy per nucleon)Separation energy:S_N = 10.210(10) MeV (first neutron)
S_P = 4.882(7) MeV (first proton)Half-life:3.73(9) minDecay constant λ:0.003097172388561 s^-1Specific activity α:1.219059371988 × 10⁺¹⁹ Bq g^-1
329475505.94278 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.1129(268) femtometer fmYear of discovery:1963

Radioactive Decay

Half-life T_½ = 3.73(9) min (minutes) respectively 2.238 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹⁵⁴Ho	99.53(13) %	2.034(10) MeV
α	¹⁵⁰Dy	0.47(13) %	4.2797(26) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁵⁴Tm, ¹⁵⁸Yb.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 86) and isobaric (same nucleon number A = 154) with Erbium-154. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 86	Isobar A = 154
48	¹³⁴Cd
49	¹³⁵In
50	¹³⁶Sn
51	¹³⁷Sb
52	¹³⁸Te
53	¹³⁹I
54	¹⁴⁰Xe
55	¹⁴¹Cs
56	¹⁴²Ba
57	¹⁴³La	¹⁵⁴La
58	¹⁴⁴Ce	¹⁵⁴Ce
59	¹⁴⁵Pr	¹⁵⁴Pr
60	¹⁴⁶Nd	¹⁵⁴Nd
61	¹⁴⁷Pm	¹⁵⁴Pm
62	¹⁴⁸Sm	¹⁵⁴Sm
63	¹⁴⁹Eu	¹⁵⁴Eu
64	¹⁵⁰Gd	¹⁵⁴Gd
65	¹⁵¹Tb	¹⁵⁴Tb
66	¹⁵²Dy	¹⁵⁴Dy
67	¹⁵³Ho	¹⁵⁴Ho
68	¹⁵⁴Er	¹⁵⁴Er
69	¹⁵⁵Tm	¹⁵⁴Tm
70	¹⁵⁶Yb	¹⁵⁴Yb
71	¹⁵⁷Lu	¹⁵⁴Lu
72	¹⁵⁸Hf	¹⁵⁴Hf
73	¹⁵⁹Ta
74	¹⁶⁰W
75	¹⁶¹Re
76	¹⁶²Os