Neodymium-139m1

Properties and data of the isotope ¹³⁹Nd.

Content

General data

Name of the isotope:Neodymium-139m1; Nd-139m1Symbol:¹³⁹Nd or 13960NdMass number A:139 (= number of nucleons)Atomic number Z:60 (= number of protons)Neutrons N:79Isotopic mass:138.91195(3) u (atomic weight of Neodymium-139m1)
Excitation energy: 231.16(5) keVNuclide mass:138.8790377 u (calculated nuclear mass without electrons)Mass excess:-82.01805 MeVMass defect:1.242080284 u (per nucleus)Nuclear binding energy:1156.99033206 MeV (per nucleus)
8.32367145 MeV (average binding energy per nucleon)Half-life:5.50(20) hDecay constant λ:3.500743336161 × 10^-5 s^-1Specific activity α:1.527678948177 × 10⁺¹⁷ Bq g^-1
4128862.0221011 Ci g^-1Spin and parity:
(nuclear angular momentum)11/2-

Radioactive Decay

Half-life T_½ = 5.50(20) h (hours) respectively 1.9800 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹³⁹Pr	87.0(10) %	?
Iso	¹³⁹Nd	13.0(10) %	0.231 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
¹³⁹Nd		29.7(5) min	3/2+
^139m2Nd	2616.9(6) keV	277(2) ns	(23/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 79) and isobaric (same nucleon number A = 139) with Neodymium-139m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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