Yttrium-89
Properties and data of the isotope 89Y.
Yttrium-89 is a radioisotope of the chemical element yttrium, which has 50 neutrons in its atomic nucleus in addition to the element-specific 39 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 89. Natural terrestrial yttrium consists of 100% Y-89.
The first mass spectroscopic detection and thus the discovery of yttrium-89 was reported in 1923 [1].
See also: List of individual Yttrium isotopes (and general data sources).
General data
Name of the isotope:Yttrium-89; Y-89Symbol:89Y or 8939YMass number A:89 (= number of nucleons)Atomic number Z:39 (= number of protons)Neutrons N:50Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.2820512820513 (= neutron-proton ratio)Neutron excess (N-Z):11Isotopic mass:88.9058382(4) u (atomic weight of Yttrium-89)Nuclide mass:88.8844445 u (calculated nuclear mass without electrons)Mass excess:-87.71115 MeVMass defect:0.83258384799998 u (per nucleus)Nuclear binding energy:775.54685891 MeV (per nucleus)
8.71400965 MeV (average binding energy per nucleon)Separation energy:SN = 11.4835(15) MeV (first neutron)
SP = 7.0785(3) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)1/2-Magnetic dipole moment:μ(μN) = -0.1374154(3)Charge radius:4.2430(21) femtometer fmYear of discovery:1923
Parent Nuclides
Direct parent isotopes are: 89Zr, 89Sr.
Occurrence
Comparison of the natural Yttrium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
| | Atomic Mass ma | Quantity | Half-life | Spin |
|---|
Yttrium
Isotopic mixture | 88.90584 u | 100 % | | |
| Isotope 89Y | 88.9058382(4) u | 100 % | stable | 1/2- |
NMR data
Nuclear magnetic properties and parameters of the NMR active Nuclide 89Y
Isotope:89Y-NMRQuantity:100 %Spin:1/2-Nuclearmagnetic moment
μ/μN:-0.1374154(3)Gyromagnetic ratio γ:-1.3162791 · 107 rad T-1 s-1
-2.09492 MHz T-1Nuclear g-factor:gl = -0.2748308Resonance frequency:v0 = 2.0949 MHz at 1 TRelative Sensitivity:[related to 1H = 1.000]:
0.00012 (H0 = const.)
0.0492 (v0 = const.)
0.000191 (at natural abundance)
relative receptivity as compared to 13C:
0.700 (at natural abundance)Reference compound:
(conditions)The IUPAC cites a solution of yttrium nitrate Y(NO3)3 in water/Deuterium Oxide H2O/D2O as the reference substance - but remains vague regarding the concentration and degree of hydration of the nitrate.
The literature often mentions the use of a 1M solution of Yttrium nitrate hexahydrate in water.Frequency ratio:Ξ(89Y) = 4.900198 % [based on the reference substance]
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 |
|---|
| 89mY | 908.97(3) keV | 15.663(5) s | 9/2+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 50) and isobaric (same nucleon number A = 89) with Yttrium-89. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 50 | Isobar A = 89 |
|---|
| 28 | 78Ni | |
| 29 | 79Cu | |
| 30 | 80Zn | |
| 31 | 81Ga | |
| 32 | 82Ge | 89Ge |
| 33 | 83As | 89As |
| 34 | 84Se | 89Se |
| 35 | 85Br | 89Br |
| 36 | 86Kr | 89Kr |
| 37 | 87Rb | 89Rb |
| 38 | 88Sr | 89Sr |
| 39 | 89Y | 89Y |
| 40 | 90Zr | 89Zr |
| 41 | 91Nb | 89Nb |
| 42 | 92Mo | 89Mo |
| 43 | 93Tc | 89Tc |
| 44 | 94Ru | 89Ru |
| 45 | 95Rh | 89Rh |
| 46 | 96Pd | |
| 47 | 97Ag | |
| 48 | 98Cd | |
| 49 | 99In | |
| 50 | 100Sn | |
External data and identifiers
Literature and References
[1] - F. W. Aston:
Further Determinations of the Constitution of the Elements by the Method of Accelerated Anode Rays.
In: Nature, 112, (1923), DOI 10.1038/112449a0.
Last update: 2026-01-26
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