Barium-138m

Properties and data of the isotope ^138mBa.

Contents

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

General data

Name of the isotope:Barium-138m; Ba-138mSymbol:^138mBa or 138m56BaMass number A:138 (= number of nucleons)Atomic number Z:56 (= number of protons)Neutrons N:82Isotopic mass:137.905247(2) u (atomic weight of Barium-138m)
Excitation energy: 2090.536(21) keVNuclide mass:137.8745286 u (calculated nuclear mass without electrons)Mass excess:-88.26185 MeVMass defect:1.243477904 u (per nucleus)Nuclear binding energy:1158.29220671 MeV (per nucleus)
8.39342179 MeV (average binding energy per nucleon)Half-life:0.85(10) μsDecay constant λ:815467.27124699 s^-1Specific activity α:3.584568448261 × 10⁺²⁷ Bq g^-1
9.688022833138 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)6+Magnetic dipole moment:μ(μ_N) = +5.88(12)Nuclear g-factor:g_l = 0.98

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
¹³⁸Ba		stable	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 82) and isobaric (same nucleon number A = 138) with Barium-138m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 82	Isobar A = 138
45	¹²⁷Rh
46	¹²⁸Pd
47	¹²⁹Ag
48	¹³⁰Cd
49	¹³¹In
50	¹³²Sn	¹³⁸Sn
51	¹³³Sb	¹³⁸Sb
52	¹³⁴Te	¹³⁸Te
53	¹³⁵I	¹³⁸I
54	¹³⁶Xe	¹³⁸Xe
55	¹³⁷Cs	¹³⁸Cs
56	¹³⁸Ba	¹³⁸Ba
57	¹³⁹La	¹³⁸La
58	¹⁴⁰Ce	¹³⁸Ce
59	¹⁴¹Pr	¹³⁸Pr
60	¹⁴²Nd	¹³⁸Nd
61	¹⁴³Pm	¹³⁸Pm
62	¹⁴⁴Sm	¹³⁸Sm
63	¹⁴⁵Eu	¹³⁸Eu
64	¹⁴⁶Gd	¹³⁸Gd
65	¹⁴⁷Tb	¹³⁸Tb
66	¹⁴⁸Dy	¹³⁸Dy
67	¹⁴⁹Ho
68	¹⁵⁰Er
69	¹⁵¹Tm
70	¹⁵²Yb
71	¹⁵³Lu
72	¹⁵⁴Hf
73	¹⁵⁵Ta
74	¹⁵⁶W