See also: List of individual Dysprosium isotopes (and general data sources).
General data
Name of the isotope:Dysprosium-156; Dy-156Symbol:156Dy or 15666DyMass number A:156 (= number of nucleons)Atomic number Z:66 (= number of protons)Neutrons N:90Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3636363636364 (= neutron-proton ratio)Neutron excess (N-Z):24Isotopic mass:155.92428(2) u (atomic weight of Dysprosium-156)Nuclide mass:155.8880768 u (calculated nuclear mass without electrons)Mass excess:-70.53273 MeVMass defect:1.372014552 u (per nucleus)Nuclear binding energy:1278.0233231 MeV (per nucleus) 8.1924572 MeV (average binding energy per nucleon)Separation energy:SN = 9.445(10) MeV (first neutron) SP = 6.568(10) MeV (first proton)Half-life:stableSpin and parity: (nuclear angular momentum)0+Charge radius:5.1622(2869) femtometer fmYear of discovery:1948
Comparison of the natural Dysprosium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
Atomic Mass ma
Quantity
Half-life
Spin
Dysprosium Isotopic mixture
162.500 u
100 %
Isotope 156Dy
155.92428(2) u
0.056(3) %
stable
0+
Isotope 158Dy
157.92442(2) u
0.095(3) %
stable
0+
Isotope 160Dy
159.92520(2) u
2.329(18) %
stable
0+
Isotope 161Dy
160.92694(2) u
18.889(42) %
stable
5/2+
Isotope 162Dy
161.92681(2) u
25.475(36) %
stable
0+
Isotope 163Dy
162.92874(2) u
24.896(42) %
stable
5/2-
Isotope 164Dy
163.92918(2) u
28.260(54) %
stable
0+
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 90) and isobaric (same nucleon number A = 156) with Dysprosium-156. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
