Samarium-141m

Properties and data of the isotope ^141mSm.

Content

General data

Name of the isotope:Samarium-141m; Sm-141mSymbol:^141mSm or 141m62SmMass number A:141 (= number of nucleons)Atomic number Z:62 (= number of protons)Neutrons N:79Isotopic mass:140.918482(9) u (atomic weight of Samarium-141m)
Excitation energy: 175.9(3) keVNuclide mass:140.8844727 u (calculated nuclear mass without electrons)Mass excess:-75.93353 MeVMass defect:1.251198348 u (per nucleus)Nuclear binding energy:1165.48375397 MeV (per nucleus)
8.26584223 MeV (average binding energy per nucleon)Half-life:22.6(2) minDecay constant λ:0.0005111704871386 s^-1Specific activity α:2.198814769279 × 10⁺¹⁸ Bq g^-1
59427426.196741 Ci g^-1Spin and parity:
(nuclear angular momentum)11/2-Magnetic dipole moment:μ(μ_N) = +0.84(2)Quadrupole moment Q:+1.60(5) barn (100 fm²)Nuclear g-factor:g_l = 0.15272727272727

Radioactive Decay

Half-life T_½ = 22.6(2) min (minutes) respectively 1.356 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹⁴¹Pm	99.69(3) %
Iso	¹⁴¹Sm	0.31(3) %

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
¹⁴¹Sm		10.2(2) min	1/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 79) and isobaric (same nucleon number A = 141) with Samarium-141m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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