Lanthanum-154

Properties and data of the isotope ¹⁵⁴La.

Contents

General data

Name of the isotope:Lanthanum-154; La-154Symbol:¹⁵⁴La or 15457LaMass number A:154 (= number of nucleons)Atomic number Z:57 (= number of protons)Neutrons N:97Isotopic mass:153.95542(32) u (atomic weight of Lanthanum-154)Nuclide mass:153.9241531 u (calculated nuclear mass without electrons)Mass excess:-41.526 MeVMass defect:1.331103676 u (per nucleus)Nuclear binding energy:1239.91508757 MeV (per nucleus)
8.05139667 MeV (average binding energy per nucleon)Separation energy:S_N = 3.54(42) MeV (first neutron)
S_P = 12.35(50) MeV (first proton)Half-life:161(15) msDecay constant λ:4.3052619910556 s^-1Specific activity α:1.694568245037 × 10⁺²² Bq g^-1
457991417577.59 Ci g^-1Spin and parity:
(nuclear angular momentum)(2-)Year of discovery:2016

Radioactive Decay

Half-life T_½ = 161(15) ms respectively 1.61 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁵⁴Ce	100 %	10.69(36) MeV
β^-, n	¹⁵³Ce	?	5.31(36) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 97) and isobaric (same nucleon number A = 154) with Lanthanum-154. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 97	Isobar A = 154
56	¹⁵³Ba
57	¹⁵⁴La	¹⁵⁴La
58	¹⁵⁵Ce	¹⁵⁴Ce
59	¹⁵⁶Pr	¹⁵⁴Pr
60	¹⁵⁷Nd	¹⁵⁴Nd
61	¹⁵⁸Pm	¹⁵⁴Pm
62	¹⁵⁹Sm	¹⁵⁴Sm
63	¹⁶⁰Eu	¹⁵⁴Eu
64	¹⁶¹Gd	¹⁵⁴Gd
65	¹⁶²Tb	¹⁵⁴Tb
66	¹⁶³Dy	¹⁵⁴Dy
67	¹⁶⁴Ho	¹⁵⁴Ho
68	¹⁶⁵Er	¹⁵⁴Er
69	¹⁶⁶Tm	¹⁵⁴Tm
70	¹⁶⁷Yb	¹⁵⁴Yb
71	¹⁶⁸Lu	¹⁵⁴Lu
72	¹⁶⁹Hf	¹⁵⁴Hf
73	¹⁷⁰Ta
74	¹⁷¹W
75	¹⁷²Re
76	¹⁷³Os
77	¹⁷⁴Ir
78	¹⁷⁵Pt
79	¹⁷⁶Au
80	¹⁷⁷Hg
81	¹⁷⁸Tl
82	¹⁷⁹Pb

External data and identifiers

Adopted Levels, Gammas:NuDat 154La

Literature and References

[1] - M. Thoennessen:
2017 Update of the discoveries of nuclides.
In: International Journal of Modern Physics E, (2018), DOI 10.1142/S0218301318300023.