Cerium-142

Properties and data of the isotope ¹⁴²Ce.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Cerium-142 is a stable natural isotope of the chemical element cerium, which has 84 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 142.

Ce-142 was identified as a distinct isotope during mass spectrometric analysis of a natural cerium tribromide sample [1]. Natural cerium contains approximately 11 wt% ¹⁴²Ce. There are no practical applications for the isotopically pure substance.

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

General data

Name of the isotope:Cerium-142; Ce-142Symbol:¹⁴²Ce or 14258CeMass number A:142 (= number of nucleons)Atomic number Z:58 (= number of protons)Neutrons N:84Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.448275862069 (= neutron-proton ratio)Neutron excess (N-Z):26Isotopic mass:141.90925(2) u (atomic weight of Cerium-142)Nuclide mass:141.8774346 u (calculated nuclear mass without electrons)Mass excess:-84.53308 MeVMass defect:1.2724548 u (per nucleus)Nuclear binding energy:1185.28401147 MeV (per nucleus)
8.3470705 MeV (average binding energy per nucleon)Separation energy:S_N = 7.1732(25) MeV (first neutron)
S_P = 8.892(5) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:4.9063(20) femtometer fmYear of discovery:1925

Radioactive Decay

The cerium isotope with mass number 142 is generally considered stable. However, there is a theoretical possibility that this nuclide, with a half-life of approximately 5 × 10¹⁶ years, could decay radioactively to neodymium-142 via a double beta decay (β^-β^-) or to barium-138 via an α decay [2].

Half-life T_½ = stable.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
2 β^-	¹⁴²Nd	?
α	¹³⁸Ba	?

Parent Nuclides

Direct parent isotopes are: ¹⁴²La, ¹⁴²Pr.

Occurrence

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

	Atomic Mass m_a	Quantity	Half-life	Spin
Cerium Isotopic mixture	140.116 u	100 %
Isotope ¹⁴²Ce	141.90925(2) u	11.114(51) %	stable	0+
Isotope ¹⁴⁰Ce	139.90544(2) u	88.449(51) %	stable	0+
Isotope ¹³⁸Ce	137.90599(7) u	0.251(2) %	stable	0+
Isotope ¹³⁶Ce	135.907129(3) u	0.186(2) %	stable	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 84) and isobaric (same nucleon number A = 142) with Cerium-142. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 84	Isobar A = 142
47	¹³¹Ag
48	¹³²Cd
49	¹³³In
50	¹³⁴Sn
51	¹³⁵Sb
52	¹³⁶Te	¹⁴²Te
53	¹³⁷I	¹⁴²I
54	¹³⁸Xe	¹⁴²Xe
55	¹³⁹Cs	¹⁴²Cs
56	¹⁴⁰Ba	¹⁴²Ba
57	¹⁴¹La	¹⁴²La
58	¹⁴²Ce	¹⁴²Ce
59	¹⁴³Pr	¹⁴²Pr
60	¹⁴⁴Nd	¹⁴²Nd
61	¹⁴⁵Pm	¹⁴²Pm
62	¹⁴⁶Sm	¹⁴²Sm
63	¹⁴⁷Eu	¹⁴²Eu
64	¹⁴⁸Gd	¹⁴²Gd
65	¹⁴⁹Tb	¹⁴²Tb
66	¹⁵⁰Dy	¹⁴²Dy
67	¹⁵¹Ho	¹⁴²Ho
68	¹⁵²Er
69	¹⁵³Tm
70	¹⁵⁴Yb
71	¹⁵⁵Lu
72	¹⁵⁶Hf
73	¹⁵⁷Ta
74	¹⁵⁸W
75	¹⁵⁹Re
76	¹⁶⁰Os

Data changes (history)

Isotopic mass: The atomic mass value of the cerium-142 isotope given here (above) corresponds to the recommendation of CIAAW and IUPAC. The more precise value of 141.9092502 ± 2.6 u can be found in nuclear databases.

External data and identifiers

Adopted Levels, Gammas:NuDat 142Ce

Literature and References

[1] - F.W. Aston:
The mass-spectra of chemical elements. - Part VI. Accelerated anode rays continued.
In: The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 49, 294, (1925), DOI 10.1080/14786442508634698.

[2] - P. Belli, R. Bernabei, F. A. Danevich, A. Incicchitti, V. I. Tretyak:
Experimental searches for rare alpha and beta decays.
In: The European Physical Journal A, 55, 140, (2019), DOI 10.1140/epja/i2019-12823-2.