Promethium-148m2

Properties and data of the isotope ¹⁴⁸Pm.

Content

General data

Name of the isotope:Promethium-148m2; Pm-148m2Symbol:¹⁴⁸Pm or 14861PmMass number A:148 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:87Isotopic mass:147.917481(6) u (atomic weight of Promethium-148m2)
Excitation energy: 137.9(3) keVNuclide mass:147.8840202 u (calculated nuclear mass without electrons)Mass excess:-76.86595 MeVMass defect:1.313693644 u (per nucleus)Nuclear binding energy:1223.69774722 MeV (per nucleus)
8.26822802 MeV (average binding energy per nucleon)Half-life:41.29(11) dDecay constant λ:1.942973313644 × 10^-7 s^-1Specific activity α:7.959768014872 × 10⁺¹⁴ Bq g^-1
21512.886526683 Ci g^-1Spin and parity:
(nuclear angular momentum)5-.6-Magnetic dipole moment:μ(μ_N) = 1.82(18)

Radioactive Decay

Half-life T_½ = 41.29(11) d respectively 3.567456 × 10⁶ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁴⁸Sm	95.8(6) %	2.6 MeV
Iso	¹⁴⁸Pm	4.2(6) %	0.137 MeV

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
¹⁴⁸Pm		5.368(7) d	1-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 87) and isobaric (same nucleon number A = 148) with Promethium-148m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 87	Isobar A = 148
49	¹³⁶In
50	¹³⁷Sn
51	¹³⁸Sb
52	¹³⁹Te
53	¹⁴⁰I
54	¹⁴¹Xe	¹⁴⁸Xe
55	¹⁴²Cs	¹⁴⁸Cs
56	¹⁴³Ba	¹⁴⁸Ba
57	¹⁴⁴La	¹⁴⁸La
58	¹⁴⁵Ce	¹⁴⁸Ce
59	¹⁴⁶Pr	¹⁴⁸Pr
60	¹⁴⁷Nd	¹⁴⁸Nd
61	¹⁴⁸Pm	¹⁴⁸Pm
62	¹⁴⁹Sm	¹⁴⁸Sm
63	¹⁵⁰Eu	¹⁴⁸Eu
64	¹⁵¹Gd	¹⁴⁸Gd
65	¹⁵²Tb	¹⁴⁸Tb
66	¹⁵³Dy	¹⁴⁸Dy
67	¹⁵⁴Ho	¹⁴⁸Ho
68	¹⁵⁵Er	¹⁴⁸Er
69	¹⁵⁶Tm	¹⁴⁸Tm
70	¹⁵⁷Yb	¹⁴⁸Yb
71	¹⁵⁸Lu
72	¹⁵⁹Hf
73	¹⁶⁰Ta
74	¹⁶¹W
75	¹⁶²Re
76	¹⁶³Os
77	¹⁶⁴Ir