Barium-137

Properties and data of the isotope ¹³⁷Ba.

Contents

General Data

Parent Nuclides

NMR Data

Isotones und Isobares

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

General data

Name of the isotope:Barium-137; Ba-137Symbol:¹³⁷Ba or 13756BaMass number A:137 (= number of nucleons)Atomic number Z:56 (= number of protons)Neutrons N:81Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4464285714286 (= neutron-proton ratio)Neutron excess (N-Z):25Isotopic mass:136.905827(2) u (atomic weight of Barium-137)Nuclide mass:136.8751086 u (calculated nuclear mass without electrons)Mass excess:-87.72158 MeVMass defect:1.234232988 u (per nucleus)Nuclear binding energy:1149.68062292 MeV (per nucleus)
8.39182936 MeV (average binding energy per nucleon)Separation energy:S_N = 6.90563(7) MeV (first neutron)
S_P = 8.6715(19) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = +0.9375(2)Charge radius:4.8314(47) femtometer fmYear of discovery:1932

Parent Nuclides

Direct parent isotopes are: ¹³⁷La, ¹³⁷Cs.

Occurrence

Comparison of the natural Barium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Barium Isotopic mixture	137.327 u	100 %
Isotope ¹³⁰Ba	129.90632(2) u	0.11(1) %	1.6 × 10²¹ a	0+
Isotope ¹³²Ba	131.9050611(11) u	0.10(1) %	stable	0+
Isotope ¹³⁴Ba	133.904508(2) u	2.42(15) %	stable	0+
Isotope ¹³⁵Ba	134.905688(2) u	6.59(10) %	stable	3/2+
Isotope ¹³⁶Ba	135.904576(2) u	7.85(24) %	stable	0+
Isotope ¹³⁷Ba	136.905827(2) u	11.23(23) %	stable	3/2+
Isotope ¹³⁸Ba	137.905247(2) u	71.70(29) %	stable	0+

NMR data

Nuclear magnetic properties and parameters of the NMR active Nuclide ¹³⁷Ba

Isotope:¹³⁷Ba-NMRQuantity:11.23(23) %Spin:3/2+Nuclearmagnetic moment
μ/μ_N:+0.9375(2)Gyromagnetic ratio γ:3.5575 · 10⁷ rad T^-1 s^-1
5.66194 MHz T^-1Nuclear g-factor:g_l = 0.625Quadrupole moment Q:+ 0.245(4) barn (100 fm²)Resonance frequency:v₀ = 4.7634 MHz at 1 TRelative Sensitivity:[related to ¹H = 1.000]:
0.00700 (H₀ = const.)
0.5594 (v₀ = const.)

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
^137mBa	661.659(3) keV	2.552(1) min	11/2-
^137m2Ba	2349.1(5) keV	0.59(10) μs	(17/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 81) and isobaric (same nucleon number A = 137) with Barium-137. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 81	Isobar A = 137
45	¹²⁶Rh
46	¹²⁷Pd
47	¹²⁸Ag
48	¹²⁹Cd
49	¹³⁰In	¹³⁷In
50	¹³¹Sn	¹³⁷Sn
51	¹³²Sb	¹³⁷Sb
52	¹³³Te	¹³⁷Te
53	¹³⁴I	¹³⁷I
54	¹³⁵Xe	¹³⁷Xe
55	¹³⁶Cs	¹³⁷Cs
56	¹³⁷Ba	¹³⁷Ba
57	¹³⁸La	¹³⁷La
58	¹³⁹Ce	¹³⁷Ce
59	¹⁴⁰Pr	¹³⁷Pr
60	¹⁴¹Nd	¹³⁷Nd
61	¹⁴²Pm	¹³⁷Pm
62	¹⁴³Sm	¹³⁷Sm
63	¹⁴⁴Eu	¹³⁷Eu
64	¹⁴⁵Gd	¹³⁷Gd
65	¹⁴⁶Tb	¹³⁷Tb
66	¹⁴⁷Dy
67	¹⁴⁸Ho
68	¹⁴⁹Er
69	¹⁵⁰Tm
70	¹⁵¹Yb
71	¹⁵²Lu
72	¹⁵³Hf