Praseodymium-129m

Properties and data of the isotope ^129mPr.

Contents

See also: list of Praseodymium isotopes.

General data

Name of the isotope:Praseodymium-129m; Pr-129mSymbol:^129mPr or 129m59PrMass number A:129 (= number of nucleons)Atomic number Z:59 (= number of protons)Neutrons N:70Isotopic mass:128.92509(3) u (atomic weight of Praseodymium-129m)
Excitation energy: 382.7(5) keVNuclide mass:128.8927262 u (calculated nuclear mass without electrons)Mass excess:-69.77822 MeVMass defect:1.143131008 u (per nucleus)Nuclear binding energy:1064.81967517 MeV (per nucleus)
8.25441609 MeV (average binding energy per nucleon)Half-life:1~ msDecay constant λ:693.14718055995 s^-1Specific activity α:3.261117154687 × 10⁺²⁴ Bq g^-1
88138301478041 Ci g^-1Spin and parity:
(nuclear angular momentum)(11/2-)

Radioactive Decay

Half-life T_½ = 1~ ms respectively 1 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β⁺	¹²⁹Ce

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
¹²⁹Pr		30(4) s	(3/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 70) and isobaric (same nucleon number A = 129) with Praseodymium-129m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 70	Isobar A = 129
39	¹⁰⁹Y
40	¹¹⁰Zr
41	¹¹¹Nb
42	¹¹²Mo
43	¹¹³Tc
44	¹¹⁴Ru
45	¹¹⁵Rh
46	¹¹⁶Pd	¹²⁹Pd
47	¹¹⁷Ag	¹²⁹Ag
48	¹¹⁸Cd	¹²⁹Cd
49	¹¹⁹In	¹²⁹In
50	¹²⁰Sn	¹²⁹Sn
51	¹²¹Sb	¹²⁹Sb
52	¹²²Te	¹²⁹Te
53	¹²³I	¹²⁹I
54	¹²⁴Xe	¹²⁹Xe
55	¹²⁵Cs	¹²⁹Cs
56	¹²⁶Ba	¹²⁹Ba
57	¹²⁷La	¹²⁹La
58	¹²⁸Ce	¹²⁹Ce
59	¹²⁹Pr	¹²⁹Pr
60	¹³⁰Nd	¹²⁹Nd
61	¹³¹Pm	¹²⁹Pm
62	¹³²Sm	¹²⁹Sm
63	¹³³Eu
64	¹³⁴Gd
65	¹³⁵Tb