Europium-151m

Properties and data of the isotope ^151mEu.

Contents

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

General data

Name of the isotope:Europium-151m; Eu-151mSymbol:^151mEu or 151m63EuMass number A:151 (= number of nucleons)Atomic number Z:63 (= number of protons)Neutrons N:88Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.3968253968254 (= neutron-proton ratio)Neutron excess (N-Z):25Excitation energy:196.245(10)Isotopic mass:150.9198569(14) u (atomic weight of Europium-151m)Nuclide mass:150.8852991 u (calculated nuclear mass without electrons)Mass excess:-74.65282 MeVMass defect:1.335632724 u (per nucleus)Nuclear binding energy:1244.13386861 MeV (per nucleus)
8.23929714 MeV (average binding energy per nucleon)Half-life:58.9(5) µsDecay constant λ:11768.203405092 s^-1Specific activity α:4.695855061984 × 10⁺²⁵ Bq g^-1
1.269150016752 × 10⁺¹⁵ Ci g^-1Spin and parity:
(nuclear angular momentum)11/2-

Radioactive Decay

Half-life T_½ = 58.9(5) µs respectively 5.89 × 10^-5 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹⁵¹Eu	100 %

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
¹⁵¹Eu		1.7 × 10¹⁸ years	5/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 88) and isobaric (same nucleon number A = 151) with Europium-151m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 88	Isobar A = 151
49	¹³⁷In
50	¹³⁸Sn
51	¹³⁹Sb
52	¹⁴⁰Te
53	¹⁴¹I
54	¹⁴²Xe
55	¹⁴³Cs	¹⁵¹Cs
56	¹⁴⁴Ba	¹⁵¹Ba
57	¹⁴⁵La	¹⁵¹La
58	¹⁴⁶Ce	¹⁵¹Ce
59	¹⁴⁷Pr	¹⁵¹Pr
60	¹⁴⁸Nd	¹⁵¹Nd
61	¹⁴⁹Pm	¹⁵¹Pm
62	¹⁵⁰Sm	¹⁵¹Sm
63	¹⁵¹Eu	¹⁵¹Eu
64	¹⁵²Gd	¹⁵¹Gd
65	¹⁵³Tb	¹⁵¹Tb
66	¹⁵⁴Dy	¹⁵¹Dy
67	¹⁵⁵Ho	¹⁵¹Ho
68	¹⁵⁶Er	¹⁵¹Er
69	¹⁵⁷Tm	¹⁵¹Tm
70	¹⁵⁸Yb	¹⁵¹Yb
71	¹⁵⁹Lu	¹⁵¹Lu
72	¹⁶⁰Hf
73	¹⁶¹Ta
74	¹⁶²W
75	¹⁶³Re
76	¹⁶⁴Os
77	¹⁶⁵Ir
78	¹⁶⁶Pt