Gadolinium-156

Properties and data of the isotope ¹⁵⁶Gd.

Contents

General data

Name of the isotope:Gadolinium-156; Gd-156Symbol:¹⁵⁶Gd or 15664GdMass number A:156 (= number of nucleons)Atomic number Z:64 (= number of protons)Neutrons N:92Isotopic mass:155.92213(2) u (atomic weight of Gadolinium-156)Nuclide mass:155.8870237 u (calculated nuclear mass without electrons)Mass excess:-72.53544 MeVMass defect:1.37584432 u (per nucleus)Nuclear binding energy:1281.59072901 MeV (per nucleus)
8.21532519 MeV (average binding energy per nucleon)Separation energy:S_N = 8.53635(7) MeV (first neutron)
S_P = 8.0058(9) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Year of discovery:1933

Parent Nuclides

Direct parent isotopes are: ¹⁵⁶Tb, ¹⁵⁶Eu.

Occurrence

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

	Atomic Mass m_a	Quantity	Half-life	Spin
Gadolinium Isotopic mixture	157.25 u	100 %
Isotope ¹⁵²Gd	151.91980(2) u	0.20(3) %	1.08(8) × 10¹⁴ a	0+
Isotope ¹⁵⁴Gd	153.92087(2) u	2.18(2) %	stable	0+
Isotope ¹⁵⁵Gd	154.92263(2) u	14.80(9) %	stable	3/2-
Isotope ¹⁵⁶Gd	155.92213(2) u	20.47(3) %	stable	0+
Isotope ¹⁵⁷Gd	156.92397(2) u	15.65(4) %	stable	3/2-
Isotope ¹⁵⁸Gd	157.92411(2) u	24.84(8) %	stable	0+
Isotope ¹⁶⁰Gd	159.92706(2) u	21.86(3) %	stable	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
^156mGd		1.3(1) μs	7-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 92) and isobaric (same nucleon number A = 156) with Gadolinium-156. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 92	Isobar A = 156
53	¹⁴⁵I
54	¹⁴⁶Xe
55	¹⁴⁷Cs
56	¹⁴⁸Ba
57	¹⁴⁹La	¹⁵⁶La
58	¹⁵⁰Ce	¹⁵⁶Ce
59	¹⁵¹Pr	¹⁵⁶Pr
60	¹⁵²Nd	¹⁵⁶Nd
61	¹⁵³Pm	¹⁵⁶Pm
62	¹⁵⁴Sm	¹⁵⁶Sm
63	¹⁵⁵Eu	¹⁵⁶Eu
64	¹⁵⁶Gd	¹⁵⁶Gd
65	¹⁵⁷Tb	¹⁵⁶Tb
66	¹⁵⁸Dy	¹⁵⁶Dy
67	¹⁵⁹Ho	¹⁵⁶Ho
68	¹⁶⁰Er	¹⁵⁶Er
69	¹⁶¹Tm	¹⁵⁶Tm
70	¹⁶²Yb	¹⁵⁶Yb
71	¹⁶³Lu	¹⁵⁶Lu
72	¹⁶⁴Hf	¹⁵⁶Hf
73	¹⁶⁵Ta	¹⁵⁶Ta
74	¹⁶⁶W	¹⁵⁶W
75	¹⁶⁷Re
76	¹⁶⁸Os
77	¹⁶⁹Ir
78	¹⁷⁰Pt
79	¹⁷¹Au
80	¹⁷²Hg