Lanthanum-141

Properties and data of the isotope ¹⁴¹La.

Content

General data

Name of the isotope:Lanthanum-141; La-141Symbol:¹⁴¹La or 14157LaMass number A:141 (= number of nucleons)Atomic number Z:57 (= number of protons)Neutrons N:84Isotopic mass:140.910969(5) u (atomic weight of Lanthanum-141)Nuclide mass:140.8797021 u (calculated nuclear mass without electrons)Mass excess:-82.93184 MeVMass defect:1.262910768 u (per nucleus)Nuclear binding energy:1176.39380293 MeV (per nucleus)
8.34321846 MeV (average binding energy per nucleon)Separation energy:S_N = 6.687(9) MeV (first neutron)
S_P = 6.951(9) MeV (first proton)Half-life:3.92(3) hDecay constant λ:4.91175723185 × 10^-5 s^-1Specific activity α:2.112806708576 × 10⁺¹⁷ Bq g^-1
5710288.4015576 Ci g^-1Spin and parity:
(nuclear angular momentum)(7/2+)Year of discovery:1951

Radioactive Decay

Half-life T_½ = 3.92(3) h (hours) respectively 1.4112 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁴¹Ce	100 %	2.501(4) MeV

Parent Nuclides

Direct parent isotope is: ¹⁴¹Ba.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 84) and isobaric (same nucleon number A = 141) with Lanthanum-141. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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