Europium-153m

Properties and data of the isotope ¹⁵³Eu.

Content

General data

Name of the isotope:Europium-153m; Eu-153mSymbol:¹⁵³Eu or 15363EuMass number A:153 (= number of nucleons)Atomic number Z:63 (= number of protons)Neutrons N:90Isotopic mass:152.92124(2) u (atomic weight of Europium-153m)
Excitation energy: 1771.0(4) keVNuclide mass:152.8866822 u (calculated nuclear mass without electrons)Mass excess:-73.36447 MeVMass defect:1.351579456 u (per nucleus)Nuclear binding energy:1258.98815379 MeV (per nucleus)
8.22868074 MeV (average binding energy per nucleon)Half-life:475(19) nsDecay constant λ:1459257.2222315 s^-1Specific activity α:5.781481936288 × 10⁺²⁷ Bq g^-1
1.562562685483 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)19/2-

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
¹⁵³Eu		stable	5/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 90) and isobaric (same nucleon number A = 153) with Europium-153m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 90	Isobar A = 153
51	¹⁴¹Sb
52	¹⁴²Te
53	¹⁴³I
54	¹⁴⁴Xe
55	¹⁴⁵Cs
56	¹⁴⁶Ba	¹⁵³Ba
57	¹⁴⁷La	¹⁵³La
58	¹⁴⁸Ce	¹⁵³Ce
59	¹⁴⁹Pr	¹⁵³Pr
60	¹⁵⁰Nd	¹⁵³Nd
61	¹⁵¹Pm	¹⁵³Pm
62	¹⁵²Sm	¹⁵³Sm
63	¹⁵³Eu	¹⁵³Eu
64	¹⁵⁴Gd	¹⁵³Gd
65	¹⁵⁵Tb	¹⁵³Tb
66	¹⁵⁶Dy	¹⁵³Dy
67	¹⁵⁷Ho	¹⁵³Ho
68	¹⁵⁸Er	¹⁵³Er
69	¹⁵⁹Tm	¹⁵³Tm
70	¹⁶⁰Yb	¹⁵³Yb
71	¹⁶¹Lu	¹⁵³Lu
72	¹⁶²Hf	¹⁵³Hf
73	¹⁶³Ta
74	¹⁶⁴W
75	¹⁶⁵Re
76	¹⁶⁶Os
77	¹⁶⁷Ir
78	¹⁶⁸Pt