Promethium-151

Properties and data of the isotope ¹⁵¹Pm.

Contents

General data

Name of the isotope:Promethium-151; Pm-151Symbol:¹⁵¹Pm or 15161PmMass number A:151 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:90Isotopic mass:150.921217(5) u (atomic weight of Promethium-151)Nuclide mass:150.8877562 u (calculated nuclear mass without electrons)Mass excess:-73.38589 MeVMass defect:1.335952392 u (per nucleus)Nuclear binding energy:1244.43163743 MeV (per nucleus)
8.24126912 MeV (average binding energy per nucleon)Separation energy:S_N = 7.86(2) MeV (first neutron)
S_P = 6.995(4) MeV (first proton)Half-life:28.40(4) hDecay constant λ:6.779608573551 × 10^-6 s^-1Specific activity α:2.721850520344 × 10⁺¹⁶ Bq g^-1
735635.27576873 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μ_N) = 1.8(2)Quadrupole moment Q:1.90(39) barn (100 fm²)Nuclear g-factor:g_l = 0.72Year of discovery:1952

Radioactive Decay

Half-life T_½ = 28.40(4) h (hours) respectively 1.02240 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁵¹Sm	100 %	1.190(4) MeV

Parent Nuclides

Direct parent isotope is: ¹⁵¹Nd.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 90) and isobaric (same nucleon number A = 151) with Promethium-151. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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