Promethium-134

Properties and data of the isotope ¹³⁴Pm.

Content

General data

Name of the isotope:Promethium-134; Pm-134Symbol:¹³⁴Pm or 13461PmMass number A:134 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:73Isotopic mass:133.92835(6) u (atomic weight of Promethium-134)Nuclide mass:133.8948892 u (calculated nuclear mass without electrons)Mass excess:-66.74155 MeVMass defect:1.18151582 u (per nucleus)Nuclear binding energy:1100.57489724 MeV (per nucleus)
8.2132455 MeV (average binding energy per nucleon)Separation energy:S_N = 9.40(8) MeV (first neutron)
S_P = 1.70(7) MeV (first proton)Half-life:5 sDecay constant λ:0.13862943611199 s^-1Specific activity α:6.277037530827 × 10⁺²⁰ Bq g^-1
16964966299.533 Ci g^-1Spin and parity:
(nuclear angular momentum)(2+)Year of discovery:1977

Radioactive Decay

Half-life T_½ = 5 s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹³⁴Nd	100 %	8.91(6) MeV

Parent Nuclides

Direct parent isotope is: ¹³⁴Sm.

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
^134mPm	+ x keV	22(1) s	(5+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 73) and isobaric (same nucleon number A = 134) with Promethium-134. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 73	Isobar A = 134
41	¹¹⁴Nb
42	¹¹⁵Mo
43	¹¹⁶Tc
44	¹¹⁷Ru
45	¹¹⁸Rh
46	¹¹⁹Pd
47	¹²⁰Ag
48	¹²¹Cd	¹³⁴Cd
49	¹²²In	¹³⁴In
50	¹²³Sn	¹³⁴Sn
51	¹²⁴Sb	¹³⁴Sb
52	¹²⁵Te	¹³⁴Te
53	¹²⁶I	¹³⁴I
54	¹²⁷Xe	¹³⁴Xe
55	¹²⁸Cs	¹³⁴Cs
56	¹²⁹Ba	¹³⁴Ba
57	¹³⁰La	¹³⁴La
58	¹³¹Ce	¹³⁴Ce
59	¹³²Pr	¹³⁴Pr
60	¹³³Nd	¹³⁴Nd
61	¹³⁴Pm	¹³⁴Pm
62	¹³⁵Sm	¹³⁴Sm
63	¹³⁶Eu	¹³⁴Eu
64	¹³⁷Gd	¹³⁴Gd
65	¹³⁸Tb
66	¹³⁹Dy
67	¹⁴⁰Ho