Promethium-159

Properties and data of the isotope ¹⁵⁹Pm.

Contents

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

General data

Name of the isotope:Promethium-159; Pm-159Symbol:¹⁵⁹Pm or 15961PmMass number A:159 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:98Isotopic mass:158.939286(11) u (atomic weight of Promethium-159)Nuclide mass:158.9058252 u (calculated nuclear mass without electrons)Mass excess:-56.55473 MeVMass defect:1.38720272 u (per nucleus)Nuclear binding energy:1292.17101046 MeV (per nucleus)
8.1268617 MeV (average binding energy per nucleon)Separation energy:S_N = 5.536(17) MeV (first neutron)
S_P = 9.79(20) MeV (first proton)Half-life:1.5(2) sDecay constant λ:0.4620981203733 s^-1Specific activity α:1.761278463291 × 10⁺²¹ Bq g^-1
47602120629.489 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2-)Year of discovery:1998

Radioactive Decay

Half-life T_½ = 1.5(2) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁵⁹Sm	100 %	5.653(12) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 98) and isobaric (same nucleon number A = 159) with Promethium-159. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 98	Isobar A = 159
57	¹⁵⁵La
58	¹⁵⁶Ce	¹⁵⁹Ce
59	¹⁵⁷Pr	¹⁵⁹Pr
60	¹⁵⁸Nd	¹⁵⁹Nd
61	¹⁵⁹Pm	¹⁵⁹Pm
62	¹⁶⁰Sm	¹⁵⁹Sm
63	¹⁶¹Eu	¹⁵⁹Eu
64	¹⁶²Gd	¹⁵⁹Gd
65	¹⁶³Tb	¹⁵⁹Tb
66	¹⁶⁴Dy	¹⁵⁹Dy
67	¹⁶⁵Ho	¹⁵⁹Ho
68	¹⁶⁶Er	¹⁵⁹Er
69	¹⁶⁷Tm	¹⁵⁹Tm
70	¹⁶⁸Yb	¹⁵⁹Yb
71	¹⁶⁹Lu	¹⁵⁹Lu
72	¹⁷⁰Hf	¹⁵⁹Hf
73	¹⁷¹Ta	¹⁵⁹Ta
74	¹⁷²W	¹⁵⁹W
75	¹⁷³Re	¹⁵⁹Re
76	¹⁷⁴Os
77	¹⁷⁵Ir
78	¹⁷⁶Pt
79	¹⁷⁷Au
80	¹⁷⁸Hg
81	¹⁷⁹Tl
82	¹⁸⁰Pb