Promethium-133

Properties and data of the isotope ¹³³Pm.

Content

General data

Name of the isotope:Promethium-133; Pm-133Symbol:¹³³Pm or 13361PmMass number A:133 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:72Isotopic mass:132.92978(5) u (atomic weight of Promethium-133)Nuclide mass:132.8963192 u (calculated nuclear mass without electrons)Mass excess:-65.40951 MeVMass defect:1.171420904 u (per nucleus)Nuclear binding energy:1091.17154355 MeV (per nucleus)
8.20429732 MeV (average binding energy per nucleon)Separation energy:S_N = 11.85(16) MeV (first neutron)
S_P = 1.27(6) MeV (first proton)Half-life:13.5(21) sDecay constant λ:0.051344235597033 s^-1Specific activity α:2.342441053872 × 10⁺²⁰ Bq g^-1
6330921767.2219 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2+)Year of discovery:1977

Radioactive Decay

Half-life T_½ = 13.5(21) s respectively 1.35 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹³³Nd	100 %	6.92(7) 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
^133mPm	129.7(7) keV	8.8 s	(11/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 72) and isobaric (same nucleon number A = 133) with Promethium-133. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 72	Isobar A = 133
40	¹¹²Zr
41	¹¹³Nb
42	¹¹⁴Mo
43	¹¹⁵Tc
44	¹¹⁶Ru
45	¹¹⁷Rh
46	¹¹⁸Pd
47	¹¹⁹Ag
48	¹²⁰Cd	¹³³Cd
49	¹²¹In	¹³³In
50	¹²²Sn	¹³³Sn
51	¹²³Sb	¹³³Sb
52	¹²⁴Te	¹³³Te
53	¹²⁵I	¹³³I
54	¹²⁶Xe	¹³³Xe
55	¹²⁷Cs	¹³³Cs
56	¹²⁸Ba	¹³³Ba
57	¹²⁹La	¹³³La
58	¹³⁰Ce	¹³³Ce
59	¹³¹Pr	¹³³Pr
60	¹³²Nd	¹³³Nd
61	¹³³Pm	¹³³Pm
62	¹³⁴Sm	¹³³Sm
63	¹³⁵Eu	¹³³Eu
64	¹³⁶Gd
65	¹³⁷Tb
66	¹³⁸Dy