Lanthanum-148

Properties and data of the isotope ¹⁴⁸La.

Content

General data

Name of the isotope:Lanthanum-148; La-148Symbol:¹⁴⁸La or 14857LaMass number A:148 (= number of nucleons)Atomic number Z:57 (= number of protons)Neutrons N:91Isotopic mass:147.932679(21) u (atomic weight of Lanthanum-148)Nuclide mass:147.9014121 u (calculated nuclear mass without electrons)Mass excess:-62.70911 MeVMass defect:1.30185518 u (per nucleus)Nuclear binding energy:1212.67028904 MeV (per nucleus)
8.19371817 MeV (average binding energy per nucleon)Separation energy:S_N = 4.102(22) MeV (first neutron)
S_P = 9.734(28) MeV (first proton)Half-life:1.26(8) sDecay constant λ:0.55011680996821 s^-1Specific activity α:2.25366048914 × 10⁺²¹ Bq g^-1
60909742949.946 Ci g^-1Spin and parity:
(nuclear angular momentum)(2-)Year of discovery:1982

Radioactive Decay

Half-life T_½ = 1.26(8) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁴⁸Ce	99.85 %	7.690(22) MeV
β^-, n	¹⁴⁷Ce	0.15(3) %	1.234(21) MeV

Parent Nuclides

Direct parent isotope is: ¹⁴⁸Ba.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 91) and isobaric (same nucleon number A = 148) with Lanthanum-148. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 91	Isobar A = 148
52	¹⁴³Te
53	¹⁴⁴I
54	¹⁴⁵Xe	¹⁴⁸Xe
55	¹⁴⁶Cs	¹⁴⁸Cs
56	¹⁴⁷Ba	¹⁴⁸Ba
57	¹⁴⁸La	¹⁴⁸La
58	¹⁴⁹Ce	¹⁴⁸Ce
59	¹⁵⁰Pr	¹⁴⁸Pr
60	¹⁵¹Nd	¹⁴⁸Nd
61	¹⁵²Pm	¹⁴⁸Pm
62	¹⁵³Sm	¹⁴⁸Sm
63	¹⁵⁴Eu	¹⁴⁸Eu
64	¹⁵⁵Gd	¹⁴⁸Gd
65	¹⁵⁶Tb	¹⁴⁸Tb
66	¹⁵⁷Dy	¹⁴⁸Dy
67	¹⁵⁸Ho	¹⁴⁸Ho
68	¹⁵⁹Er	¹⁴⁸Er
69	¹⁶⁰Tm	¹⁴⁸Tm
70	¹⁶¹Yb	¹⁴⁸Yb
71	¹⁶²Lu
72	¹⁶³Hf
73	¹⁶⁴Ta
74	¹⁶⁵W
75	¹⁶⁶Re
76	¹⁶⁷Os
77	¹⁶⁸Ir
78	¹⁶⁹Pt
79	¹⁷⁰Au
80	¹⁷¹Hg