Promethium-148

Properties and data of the isotope ¹⁴⁸Pm.

Contents

General data

Name of the isotope:Promethium-148; Pm-148Symbol: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-148)Nuclide 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)Separation energy:S_N = 5.895(6) MeV (first neutron)
S_P = 6.008(6) MeV (first proton)Half-life:5.368(7) dDecay constant λ:1.494511328620 × 10^-6 s^-1Specific activity α:6.122556284167 × 10⁺¹⁵ Bq g^-1
165474.49416668 Ci g^-1Spin and parity:
(nuclear angular momentum)1-Magnetic dipole moment:μ(μ_N) = 1.84(19)Quadrupole moment Q:+0.20 barn (100 fm²)Nuclear g-factor:g_l = 1.84Year of discovery:1947

Radioactive Decay

Half-life T_½ = 5.368(7) d respectively 4.637952 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁴⁸Sm	100 %	2.471(6) 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
^148m2Pm	137.9(3) keV	41.29(11) d	5-,6-

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-148. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	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