Samarium-145

Properties and data of the isotope ¹⁴⁵Sm.

Content

General data

Name of the isotope:Samarium-145; Sm-145Symbol:¹⁴⁵Sm or 14562SmMass number A:145 (= number of nucleons)Atomic number Z:62 (= number of protons)Neutrons N:83Isotopic mass:144.9134172(17) u (atomic weight of Samarium-145)Nuclide mass:144.8794079 u (calculated nuclear mass without electrons)Mass excess:-80.65136 MeVMass defect:1.290922812 u (per nucleus)Nuclear binding energy:1202.48685384 MeV (per nucleus)
8.29301279 MeV (average binding energy per nucleon)Separation energy:S_N = 6.7571(3) MeV (first neutron)
S_P = 6.5242(27) MeV (first proton)Half-life:340(3) dDecay constant λ:2.359248402178 × 10^-8 s^-1Specific activity α:98664765288178 Bq g^-1
2666.6152780589 Ci g^-1Spin and parity:
(nuclear angular momentum)7/2-Magnetic dipole moment:μ(μ_N) = - 1.12Quadrupole moment Q:0.60(17) barn (100 fm²)Nuclear g-factor:g_l = -0.32Charge radius:4.9651(34) femtometer fmYear of discovery:1947

Radioactive Decay

Half-life T_½ = 340(3) d respectively 2.938 × 10⁷ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE	¹⁴⁵Pm	100 %	0.616(3) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁴⁵Eu, ¹⁴⁹Gd.

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
^145mSm	8786.2(7) keV	0.96 μs	(49/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 83) and isobaric (same nucleon number A = 145) with Samarium-145. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 83	Isobar A = 145
46	¹²⁹Pd
47	¹³⁰Ag
48	¹³¹Cd
49	¹³²In
50	¹³³Sn
51	¹³⁴Sb
52	¹³⁵Te
53	¹³⁶I	¹⁴⁵I
54	¹³⁷Xe	¹⁴⁵Xe
55	¹³⁸Cs	¹⁴⁵Cs
56	¹³⁹Ba	¹⁴⁵Ba
57	¹⁴⁰La	¹⁴⁵La
58	¹⁴¹Ce	¹⁴⁵Ce
59	¹⁴²Pr	¹⁴⁵Pr
60	¹⁴³Nd	¹⁴⁵Nd
61	¹⁴⁴Pm	¹⁴⁵Pm
62	¹⁴⁵Sm	¹⁴⁵Sm
63	¹⁴⁶Eu	¹⁴⁵Eu
64	¹⁴⁷Gd	¹⁴⁵Gd
65	¹⁴⁸Tb	¹⁴⁵Tb
66	¹⁴⁹Dy	¹⁴⁵Dy
67	¹⁵⁰Ho	¹⁴⁵Ho
68	¹⁵¹Er	¹⁴⁵Er
69	¹⁵²Tm	¹⁴⁵Tm
70	¹⁵³Yb
71	¹⁵⁴Lu
72	¹⁵⁵Hf
73	¹⁵⁶Ta
74	¹⁵⁷W