Cerium-145

Properties and data of the isotope ¹⁴⁵Ce.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Cerium-145 is a radioisotope of the chemical element cerium, which has 87 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 145. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹⁴⁵Ce is exclusively for academic purposes.

Cerium-145 was identified in 1954 by neutron irradiation of uranyl nitrate in a research reactor. After chemical separation of the cerium and praseodymium components, an activity with a half-life of approximately three minutes was detected. The signal was assigned to cerium-145 by correlation with the characteristic activity of the daughter nuclide praseodymium-145, whose decay had a half-life of approximately six hours. The observed temporal decline in praseodymium activity during successive sampling clearly confirmed its origin from a short-lived parent isotope [1].

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

General data

Name of the isotope:Cerium-145; Ce-145Symbol:¹⁴⁵Ce or 14558CeMass number A:145 (= number of nucleons)Atomic number Z:58 (= number of protons)Neutrons N:87Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.5 (= neutron-proton ratio)Neutron excess (N-Z):29Isotopic mass:144.91727(4) u (atomic weight of Cerium-145)Nuclide mass:144.8854546 u (calculated nuclear mass without electrons)Mass excess:-77.0625 MeVMass defect:1.290429548 u (per nucleus)Nuclear binding energy:1202.02738138 MeV (per nucleus)
8.28984401 MeV (average binding energy per nucleon)Separation energy:S_N = 4.706(34) MeV (first neutron)
S_P = 9.506(36) MeV (first proton)Half-life:3.01(6) minDecay constant λ:0.0038380242555922 s^-1Specific activity α:1.605077964654 × 10⁺¹⁹ Bq g^-1
433804855.31214 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2-)Year of discovery:1954

Radioactive Decay

Half-life T_½ = 3.01(6) min (minutes) respectively 1.806 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁴⁵Pr	100 %	2.56(3) MeV

Parent Nuclides

Direct parent isotope is: ¹⁴⁵La.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 87) and isobaric (same nucleon number A = 145) with Cerium-145. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 87	Isobar A = 145
49	¹³⁶In
50	¹³⁷Sn
51	¹³⁸Sb
52	¹³⁹Te
53	¹⁴⁰I	¹⁴⁵I
54	¹⁴¹Xe	¹⁴⁵Xe
55	¹⁴²Cs	¹⁴⁵Cs
56	¹⁴³Ba	¹⁴⁵Ba
57	¹⁴⁴La	¹⁴⁵La
58	¹⁴⁵Ce	¹⁴⁵Ce
59	¹⁴⁶Pr	¹⁴⁵Pr
60	¹⁴⁷Nd	¹⁴⁵Nd
61	¹⁴⁸Pm	¹⁴⁵Pm
62	¹⁴⁹Sm	¹⁴⁵Sm
63	¹⁵⁰Eu	¹⁴⁵Eu
64	¹⁵¹Gd	¹⁴⁵Gd
65	¹⁵²Tb	¹⁴⁵Tb
66	¹⁵³Dy	¹⁴⁵Dy
67	¹⁵⁴Ho	¹⁴⁵Ho
68	¹⁵⁵Er	¹⁴⁵Er
69	¹⁵⁶Tm	¹⁴⁵Tm
70	¹⁵⁷Yb
71	¹⁵⁸Lu
72	¹⁵⁹Hf
73	¹⁶⁰Ta
74	¹⁶¹W
75	¹⁶²Re
76	¹⁶³Os
77	¹⁶⁴Ir
78	¹⁶⁵Pt

External data and identifiers

Adopted Levels, Gammas:NuDat 145Ce

Literature and References

[1] - S. S. Markowitz, W. Bernstein, S. Katcoff:
A New 3.0-min Ce Fission Product and its 5.95-hr Pr Daughter.
In: Physical Review, 93, 178, (1954), DOI 10.1103/PhysRev.93.178.