Praseodymium-138m

Properties and data of the isotope ^138mPr.

Contents

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

General data

Name of the isotope:Praseodymium-138m; Pr-138mSymbol:^138mPr or 138m59PrMass number A:138 (= number of nucleons)Atomic number Z:59 (= number of protons)Neutrons N:79Isotopic mass:137.910752(12) u (atomic weight of Praseodymium-138m)
Excitation energy: 364(23) keVNuclide mass:137.8783882 u (calculated nuclear mass without electrons)Mass excess:-83.13398 MeVMass defect:1.235453252 u (per nucleus)Nuclear binding energy:1150.81729152 MeV (per nucleus)
8.33925574 MeV (average binding energy per nucleon)Half-life:2.03(2) hDecay constant λ:9.484772585658 × 10^-5 s^-1Specific activity α:4.169243542722 × 10⁺¹⁷ Bq g^-1
11268225.791143 Ci g^-1Spin and parity:
(nuclear angular momentum)7-

Radioactive Decay

Half-life T_½ = 2.03(2) h (hours) respectively 7.308 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹³⁸Ce	100 %

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
¹³⁸Pr		1.45(5) min	1+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 79) and isobaric (same nucleon number A = 138) with Praseodymium-138m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 79	Isobar A = 138
44	¹²³Ru
45	¹²⁴Rh
46	¹²⁵Pd
47	¹²⁶Ag
48	¹²⁷Cd
49	¹²⁸In
50	¹²⁹Sn	¹³⁸Sn
51	¹³⁰Sb	¹³⁸Sb
52	¹³¹Te	¹³⁸Te
53	¹³²I	¹³⁸I
54	¹³³Xe	¹³⁸Xe
55	¹³⁴Cs	¹³⁸Cs
56	¹³⁵Ba	¹³⁸Ba
57	¹³⁶La	¹³⁸La
58	¹³⁷Ce	¹³⁸Ce
59	¹³⁸Pr	¹³⁸Pr
60	¹³⁹Nd	¹³⁸Nd
61	¹⁴⁰Pm	¹³⁸Pm
62	¹⁴¹Sm	¹³⁸Sm
63	¹⁴²Eu	¹³⁸Eu
64	¹⁴³Gd	¹³⁸Gd
65	¹⁴⁴Tb	¹³⁸Tb
66	¹⁴⁵Dy	¹³⁸Dy
67	¹⁴⁶Ho
68	¹⁴⁷Er
69	¹⁴⁸Tm
70	¹⁴⁹Yb
71	¹⁵⁰Lu