Samarium-144

Properties and data of the isotope ¹⁴⁴Sm.

Content

General data

Name of the isotope:Samarium-144; Sm-144Symbol:¹⁴⁴Sm or 14462SmMass number A:144 (= number of nucleons)Atomic number Z:62 (= number of protons)Neutrons N:82Isotopic mass:143.91201(2) u (atomic weight of Samarium-144)Nuclide mass:143.8780007 u (calculated nuclear mass without electrons)Mass excess:-81.96216 MeVMass defect:1.283665096 u (per nucleus)Nuclear binding energy:1195.72633493 MeV (per nucleus)
8.3036551 MeV (average binding energy per nucleon)Separation energy:S_N = 10.5197(23) MeV (first neutron)
S_P = 6.2939(27) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:4.9524(34) femtometer fmYear of discovery:1933

Parent Nuclides

Direct parent isotopes are: ¹⁴⁴Eu, ¹⁴⁴Pm, ¹⁴⁸Gd.

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 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-
Isotope ¹⁴⁶Sm	145.913047(3) u	[trace]	9.20 (26) × 10⁷ a	0+

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
^144mSm	2323.60(8) keV	880(25) ns	6+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 82) and isobaric (same nucleon number A = 144) with Samarium-144. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 82	Isobar A = 144
45	¹²⁷Rh
46	¹²⁸Pd
47	¹²⁹Ag
48	¹³⁰Cd
49	¹³¹In
50	¹³²Sn
51	¹³³Sb
52	¹³⁴Te
53	¹³⁵I	¹⁴⁴I
54	¹³⁶Xe	¹⁴⁴Xe
55	¹³⁷Cs	¹⁴⁴Cs
56	¹³⁸Ba	¹⁴⁴Ba
57	¹³⁹La	¹⁴⁴La
58	¹⁴⁰Ce	¹⁴⁴Ce
59	¹⁴¹Pr	¹⁴⁴Pr
60	¹⁴²Nd	¹⁴⁴Nd
61	¹⁴³Pm	¹⁴⁴Pm
62	¹⁴⁴Sm	¹⁴⁴Sm
63	¹⁴⁵Eu	¹⁴⁴Eu
64	¹⁴⁶Gd	¹⁴⁴Gd
65	¹⁴⁷Tb	¹⁴⁴Tb
66	¹⁴⁸Dy	¹⁴⁴Dy
67	¹⁴⁹Ho	¹⁴⁴Ho
68	¹⁵⁰Er	¹⁴⁴Er
69	¹⁵¹Tm	¹⁴⁴Tm
70	¹⁵²Yb
71	¹⁵³Lu
72	¹⁵⁴Hf
73	¹⁵⁵Ta
74	¹⁵⁶W