Cerium-137

Properties and data of the isotope ¹³⁷Ce.

Contents

General Data

Radioactive Decay

Parent Nuclides

NMR Data

Isotones und Isobares

Literature

Cerium-137 is a radioisotope of the chemical element cerium, which has 79 neutrons in its atomic nucleus in addition to the element-specific 58 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 137. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹³⁷Ce is exclusively for academic purposes.

Cerium-137 was first identified in 1948. The isotope was produced by bombarding lanthanum with deuterons (hydrogen-2 nuclei) in the reaction ¹³⁹La(d,4n)¹³⁷ using deuteron energies up to 40 MeV. After chemical separation of the cerium fraction, beta and X-ray spectra were measured [1].

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

General data

Name of the isotope:Cerium-137; Ce-137Symbol:¹³⁷Ce or 13758CeMass number A:137 (= number of nucleons)Atomic number Z:58 (= number of protons)Neutrons N:79Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.3620689655172 (= neutron-proton ratio)Neutron excess (N-Z):21Isotopic mass:136.9077624(4) u (atomic weight of Cerium-137)Nuclide mass:136.875947 u (calculated nuclear mass without electrons)Mass excess:-85.91877 MeVMass defect:1.23061782 u (per nucleus)Nuclear binding energy:1146.31311562 MeV (per nucleus)
8.36724902 MeV (average binding energy per nucleon)Separation energy:S_N = 7.48153(16) MeV (first neutron)
S_P = 7.710(53) MeV (first proton)Half-life:9.0(3) hDecay constant λ:2.139343149876 × 10^-5 s^-1Specific activity α:9.47310720315 × 10⁺¹⁶ Bq g^-1
2560299.244097 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = 0.96(4)Year of discovery:1948

Radioactive Decay

Half-life T_½ = 9.0(3) h (hours) respectively 3.2400 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹³⁷La	100 %	1.2221(16) MeV

Parent Nuclides

Direct parent isotope is: ¹³⁷Pr.

NMR data

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

Isotope:¹³⁷Ce-NMRQuantity:Does not occur in nature!Spin:3/2+Nuclearmagnetic moment
μ/μ_N:0.96(4)Nuclear g-factor:g_l = 0.64Resonance frequency:v₀ = 4.88 MHz at 1 TRelative Sensitivity:[related to ¹H = 1.000]:
0.00752 (H₀ = const.)
0.5729 (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
^137mCe	254.29(5) keV	34.4(3) h	11/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 79) and isobaric (same nucleon number A = 137) with Cerium-137. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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

External data and identifiers

Adopted Levels, Gammas:NuDat 137Ce

Literature and References

[1] - J. B. Chubbuck and I. Perlman:
Neutron Deficient Isotopes of Cerium and Lanthanum.
In: Physical Review, 74, 982, (1948), DOI 10.1103/PhysRev.74.982.2.