Erbium-151m

Properties and data of the isotope ¹⁵¹Er.

Content

General data

Name of the isotope:Erbium-151m; Er-151mSymbol:¹⁵¹Er or 15168ErMass number A:151 (= number of nucleons)Atomic number Z:68 (= number of protons)Neutrons N:83Isotopic mass:150.937449(18) u (atomic weight of Erbium-151m)
Excitation energy: 2585.0(5) keVNuclide mass:150.9001489 u (calculated nuclear mass without electrons)Mass excess:-58.26588 MeVMass defect:1.313841204 u (per nucleus)Nuclear binding energy:1223.83519848 MeV (per nucleus)
8.10486886 MeV (average binding energy per nucleon)Half-life:0.58(2) sDecay constant λ:1.195081345793 s^-1Specific activity α:4.797965468965 × 10⁺²¹ Bq g^-1
129674742404.47 Ci g^-1Spin and parity:
(nuclear angular momentum)(27/2-)

Radioactive Decay

Half-life T_½ = 0.58(2) s respectively 5.8 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹⁵¹Ho	4.7(4) %
Iso	¹⁵¹Er	95.3(4) %

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
¹⁵¹Er		23.5(20) s	(7/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 83) and isobaric (same nucleon number A = 151) with Erbium-151m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 83	Isobar A = 151
46	¹²⁹Pd
47	¹³⁰Ag
48	¹³¹Cd
49	¹³²In
50	¹³³Sn
51	¹³⁴Sb
52	¹³⁵Te
53	¹³⁶I
54	¹³⁷Xe
55	¹³⁸Cs	¹⁵¹Cs
56	¹³⁹Ba	¹⁵¹Ba
57	¹⁴⁰La	¹⁵¹La
58	¹⁴¹Ce	¹⁵¹Ce
59	¹⁴²Pr	¹⁵¹Pr
60	¹⁴³Nd	¹⁵¹Nd
61	¹⁴⁴Pm	¹⁵¹Pm
62	¹⁴⁵Sm	¹⁵¹Sm
63	¹⁴⁶Eu	¹⁵¹Eu
64	¹⁴⁷Gd	¹⁵¹Gd
65	¹⁴⁸Tb	¹⁵¹Tb
66	¹⁴⁹Dy	¹⁵¹Dy
67	¹⁵⁰Ho	¹⁵¹Ho
68	¹⁵¹Er	¹⁵¹Er
69	¹⁵²Tm	¹⁵¹Tm
70	¹⁵³Yb	¹⁵¹Yb
71	¹⁵⁴Lu	¹⁵¹Lu
72	¹⁵⁵Hf
73	¹⁵⁶Ta
74	¹⁵⁷W