Scandium-45
Properties and data of the isotope 45Sc.
Scandium-45 is a stable isotope of the chemical element scandium, which has 24 neutrons in its atomic nucleus in addition to the element-specific 21 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 45.
The first detection of the nuclide was achieved using accelerated anode rays with a spectrograph in 1923 [1].
See also: List of individual Scandium isotopes (and general data sources).
General data
Name of the isotope:Scandium-45; Sc-45Symbol:45Sc or 4521ScMass number A:45 (= number of nucleons)Atomic number Z:21 (= number of protons)Neutrons N:24Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.1428571428571 (= neutron-proton ratio)Neutron excess (N-Z):3Isotopic mass:44.955908(5) u (atomic weight of Scandium-45)Nuclide mass:44.944388 u (calculated nuclear mass without electrons)Mass excess:-41.07143 MeVMass defect:0.41637565600001 u (per nucleus)Nuclear binding energy:387.85142531 MeV (per nucleus)
8.61892056 MeV (average binding energy per nucleon)Separation energy:SN = 11.3276(19) MeV (first neutron)
SP = 6.8926(7) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)7/2-Magnetic dipole moment:μ(μN) = +4.75400(8)Charge radius:3.5459(25) femtometer fmMirror nucleus:Chromium-45Year of discovery:1923
Parent Nuclides
Direct parent isotopes are: 45Ca, 45Ti.
Occurrence
Comparison of the natural Scandium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
| | Atomic Mass ma | Quantity | Half-life | Spin |
|---|
Scandium
Isotopic mixture | 44.955908 u | 100 % | | |
| Isotope 45Sc | 44.955908(5) u | 100 % | stable | 7/2- |
NMR data
Nuclear magnetic properties and parameters of the NMR active Nuclide 45Sc
Isotope:45Sc-NMRQuantity:100 %Spin:7/2-Nuclearmagnetic moment
μ/μN:+4.75400(8)Gyromagnetic ratio γ:6.5081 · 107 rad T-1 s-1
10.35796 MHz T-1Nuclear g-factor:gl = 1.3582857142857Quadrupole moment Q:- 0.220(2) barn (100 fm2)Resonance frequency:v0 = 10.3591 MHz at 1 TRelative Sensitivity:[related to 1H = 1.000]:
0.30244 (H0 = const.)
5.1094 (v0 = const.)
0.302 (at natural abundance)
relative receptivity as compared to 13C:
1780 (at natural abundance)Reference compound:
(conditions)0.06 M scandium nitrate (Sc(NO3)3) in Deuterium Oxide (D2O)Frequency ratio:Ξ(45Sc) = 24.291747 % [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 |
|---|
| 45mSc | 12.40(5) keV | 318(7) ms | 3/2+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 24) and isobaric (same nucleon number A = 45) with Scandium-45. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 24 | Isobar A = 45 |
|---|
| 10 | 34Ne | |
| 11 | 35Na | |
| 12 | 36Mg | |
| 13 | 37Al | |
| 14 | 38Si | |
| 15 | 39P | 45P |
| 16 | 40S | 45S |
| 17 | 41Cl | 45Cl |
| 18 | 42Ar | 45Ar |
| 19 | 43K | 45K |
| 20 | 44Ca | 45Ca |
| 21 | 45Sc | 45Sc |
| 22 | 46Ti | 45Ti |
| 23 | 47V | 45V |
| 24 | 48Cr | 45Cr |
| 25 | 49Mn | 45Mn |
| 26 | 50Fe | 45Fe |
| 27 | 51Co | |
| 28 | 52Ni | |
| 29 | 53Cu | |
| 30 | 54Zn | |
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: 2025-12-16
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