Europium-142

Properties and data of the isotope ¹⁴²Eu.

Contents

General data

Name of the isotope:Europium-142; Eu-142Symbol:¹⁴²Eu or 14263EuMass number A:142 (= number of nucleons)Atomic number Z:63 (= number of protons)Neutrons N:79Isotopic mass:141.92344(3) u (atomic weight of Europium-142)Nuclide mass:141.8888822 u (calculated nuclear mass without electrons)Mass excess:-71.31518 MeVMass defect:1.25406538 u (per nucleus)Nuclear binding energy:1168.15437708 MeV (per nucleus)
8.22643928 MeV (average binding energy per nucleon)Separation energy:S_N = 9.46(4) MeV (first neutron)
S_P = 2.67(3) MeV (first proton)Half-life:2.34(12) sDecay constant λ:0.29621674382904 s^-1Specific activity α:1.265148196035 × 10⁺²¹ Bq g^-1
34193194487.449 Ci g^-1Spin and parity:
(nuclear angular momentum)1+Magnetic dipole moment:μ(μ_N) = + 1.536(19)Quadrupole moment Q:0.12(5) barn (100 fm²)Nuclear g-factor:g_l = 1.536Charge radius:4.9607(91) femtometer fmYear of discovery:1966

Radioactive Decay

Half-life T_½ = 2.34(12) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁴²Sm	100 %	4.35 MeV

Parent Nuclides

Direct parent isotope is: ¹⁴²Gd.

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^142mEu	460 keV	1.223(8) min	8-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 79) and isobaric (same nucleon number A = 142) with Europium-142. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 79	Isobar A = 142
44	¹²³Ru
45	¹²⁴Rh
46	¹²⁵Pd
47	¹²⁶Ag
48	¹²⁷Cd
49	¹²⁸In
50	¹²⁹Sn
51	¹³⁰Sb
52	¹³¹Te	¹⁴²Te
53	¹³²I	¹⁴²I
54	¹³³Xe	¹⁴²Xe
55	¹³⁴Cs	¹⁴²Cs
56	¹³⁵Ba	¹⁴²Ba
57	¹³⁶La	¹⁴²La
58	¹³⁷Ce	¹⁴²Ce
59	¹³⁸Pr	¹⁴²Pr
60	¹³⁹Nd	¹⁴²Nd
61	¹⁴⁰Pm	¹⁴²Pm
62	¹⁴¹Sm	¹⁴²Sm
63	¹⁴²Eu	¹⁴²Eu
64	¹⁴³Gd	¹⁴²Gd
65	¹⁴⁴Tb	¹⁴²Tb
66	¹⁴⁵Dy	¹⁴²Dy
67	¹⁴⁶Ho	¹⁴²Ho
68	¹⁴⁷Er
69	¹⁴⁸Tm
70	¹⁴⁹Yb
71	¹⁵⁰Lu