Samarium-149

Properties and data of the isotope ¹⁴⁹Sm.

Content

General data

Name of the isotope:Samarium-149; Sm-149Symbol:¹⁴⁹Sm or 14962SmMass number A:149 (= number of nucleons)Atomic number Z:62 (= number of protons)Neutrons N:87Isotopic mass:148.91719(2) u (atomic weight of Samarium-149)Nuclide mass:148.8831807 u (calculated nuclear mass without electrons)Mass excess:-77.13702 MeVMass defect:1.321809676 u (per nucleus)Nuclear binding energy:1231.25778234 MeV (per nucleus)
8.26347505 MeV (average binding energy per nucleon)Separation energy:S_N = 5.8707(9) MeV (first neutron)
S_P = 7.559(6) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)7/2-Magnetic dipole moment:μ(μ_N) = - 0.6718Charge radius:5.0134(35) femtometer fmYear of discovery:1933

Parent Nuclides

Direct parent isotopes are: ¹⁴⁹Eu, ¹⁴⁹Pm.

Occurrence

Comparison of the natural Samarium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Samarium Isotopic mixture	150.36 u	100 %
Isotope ¹⁴⁴Sm	143.91201(2) u	3.08(4) %	stable	0+
Isotope ¹⁴⁶Sm	145.913047(3) u	[trace]	6.8(7) × 10⁷ a	0+
Isotope ¹⁴⁸Sm	147.91483(2) u	11.25(9) %	7(3)×10¹⁵ a	0+
Isotope ¹⁴⁹Sm	148.91719(2) u	13.82(10) %	stable	7/2-
Isotope ¹⁵⁰Sm	149.91728(2) u	7.37(9) %	stable	0+
Isotope ¹⁵²Sm	151.91974(2) u	26.74(9) %	stable	0+
Isotope ¹⁵⁴Sm	153.92222(2) u	22.74(14) %	stable	0+
Isotope ¹⁴⁷Sm	146.91490(2) u	15.00(14) %	1.0625(38) × 10¹¹ a	7/2-

NMR data

Nuclear magnetic properties of the NMR active Nuclide ¹⁴⁹Sm

Isotope:¹⁴⁹Sm-NMRQuantity:13.82(10) %Spin:7/2-Nuclearmagnetic moment
μ/μ_N:- 0.6718Gyromagnetic ratio γ:0.9175 · 10⁷ rad T^-1 s^-1Nuclear g-factor:g_l = -0.19194285714286Quadrupole moment Q:+ 0.75(7) barn (100 fm²)Resonance frequency:v₀ = 1.4631 at 1 TRelative Sensitivity:0.00085 (H₀ = const.)
0.7216 (v₀ = const.)
[related to ¹H = 1.000]

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 87) and isobaric (same nucleon number A = 149) with Samarium-149. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 87	Isobar A = 149
49	¹³⁶In
50	¹³⁷Sn
51	¹³⁸Sb
52	¹³⁹Te
53	¹⁴⁰I
54	¹⁴¹Xe
55	¹⁴²Cs	¹⁴⁹Cs
56	¹⁴³Ba	¹⁴⁹Ba
57	¹⁴⁴La	¹⁴⁹La
58	¹⁴⁵Ce	¹⁴⁹Ce
59	¹⁴⁶Pr	¹⁴⁹Pr
60	¹⁴⁷Nd	¹⁴⁹Nd
61	¹⁴⁸Pm	¹⁴⁹Pm
62	¹⁴⁹Sm	¹⁴⁹Sm
63	¹⁵⁰Eu	¹⁴⁹Eu
64	¹⁵¹Gd	¹⁴⁹Gd
65	¹⁵²Tb	¹⁴⁹Tb
66	¹⁵³Dy	¹⁴⁹Dy
67	¹⁵⁴Ho	¹⁴⁹Ho
68	¹⁵⁵Er	¹⁴⁹Er
69	¹⁵⁶Tm	¹⁴⁹Tm
70	¹⁵⁷Yb	¹⁴⁹Yb
71	¹⁵⁸Lu	¹⁴⁹Lu
72	¹⁵⁹Hf
73	¹⁶⁰Ta
74	¹⁶¹W
75	¹⁶²Re
76	¹⁶³Os
77	¹⁶⁴Ir