Isotopes of scandium

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Isotopes of scandium  (21Sc)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
44m2Sc synth 58.61 h IT 44Sc
γ 44Sc
ε 44Ca
45Sc100% stable
46Scsynth83.79 d β− 46Ti
γ–
47Scsynth80.38 hβ− 47Ti
γ–
48Scsynth43.67 hβ− 48Ti
γ–
Standard atomic weight Ar°(Sc)
  • 44.955907±0.000004
  • 44.956±0.001 (abridged) [2] [3]

Naturally occurring scandium (21Sc) is composed of one stable isotope, 45Sc. Twenty-five radioisotopes have been characterized, with the most stable being 46Sc with a half-life of 83.8 days, 47Sc with a half-life of 3.35 days, and 48Sc with a half-life of 43.7 hours and 44Sc with a half-life of 3.97 hours. All the remaining isotopes have half-lives that are less than four hours, and the majority of these have half-lives that are less than two minutes, the least stable being proton unbound 39Sc with a half-life shorter than 300 nanoseconds. This element also has 13 meta states with the most stable being 44m2Sc (t1/2 58.6 h).

The isotopes of scandium range in atomic weight from 39 u (39Sc) to 62 u (62Sc). The primary decay mode at masses lower than the only stable isotope, 45Sc, is beta-plus or electron capture, and the primary mode at masses above it is beta-minus. The primary decay products at atomic weights below 45Sc are calcium isotopes and the primary products from higher atomic weights are titanium isotopes.

List of isotopes

Nuclide
[n 1] 		Z N Isotopic mass (Da)
[n 2] [n 3] 		Half-life
[n 4] 		Decay
mode
[n 5] 		Daughter
isotope
[n 6] 		Spin and
parity
[n 7] [n 4] 		Natural abundance (mole fraction)
Excitation energyNormal proportionRange of variation
39Sc211838.984790(26)<300 nsp38Ca(7/2−)#
40Sc211939.977967(3)182.3(7) ms β+ (99.54%)40Ca4-
β+, p (.44%)39K
β+, α (.017%)36Ar
41Sc212040.96925113(24)596.3(17) msβ+41Ca7/2−
42Sc212141.96551643(29)681.3(7) msβ+42Ca0+
42mSc616.28(6) keV61.7(4) sβ+42Ca(7, 5, 6)+
43Sc212242.9611507(20)3.891(12) hβ+43Ca7/2−
43m1Sc151.4(2) keV438(7) μs3/2+
43m2Sc3123.2(3) keV470(4) ns(19/2)−
44Sc 212343.9594028(19)3.97(4) hβ+44Ca2+
44m1Sc67.8680(14) keV154.2(8) ns1−
44m2Sc270.95(20) keV58.61(10) h IT (98.8%)44Sc6+
β+ (1.2%)44Ca
44m3Sc146.224(22) keV50.4(7) μs0-
45Sc212444.9559119(9)Stable7/2−1.0000
45mSc12.40(5) keV318(7) msIT45Sc3/2+
46Sc212545.9551719(9)83.79(4) dβ−46Ti4+
46m1Sc52.011(1) keV9.4(8) μs6+
46m2Sc142.528(7) keV18.75(4) sIT46Sc1−
47Sc212646.9524075(22)3.3492(6) dβ−47Ti7/2−
47mSc766.83(9) keV272(8) ns(3/2)+
48Sc212747.952231(6)43.67(9) hβ−48Ti6+
49Sc212848.950024(4)57.2(2) minβ−49Ti7/2−
50Sc212949.952188(17)102.5(5) sβ−50Ti5+
50mSc256.895(10) keV350(40) msIT (97.5%)50Sc2+, 3+
β− (2.5%)50Ti
51Sc213050.953603(22)12.4(1) sβ−51Ti(7/2)−
52Sc213151.95668(21)8.2(2) sβ−52Ti3(+)
53Sc213252.95961(32)#2.4(0.6) sβ− (>99.9%)53Ti(7/2−)#
β−, n (<.1%)52Ti
54Sc213353.96326(40)260(30) msβ− (>99.9%)54Ti3+#
β−, n (<.1%)53Ti
54mSc110(3) keV7(5) μs(5+)
55Sc213454.96824(79)0.115(15) sβ− (>99.9%)55Ti7/2−#
β−, n (<.1%)54Ti
56Sc213555.97287(75)#35(5) msβ−56Ti(1+)
57Sc213656.97779(75)#13(4) msβ−57Ti7/2−#
58Sc213757.98371(86)#12(5) msβ−58Ti(3+)#
59Sc213858.98922(97)#10# msβ−, n58Ti7/2−#
β−59Ti
60Sc213959.99571(97)#3# ms
(>620 ns)		β−60Ti3+#
β−, n59Ti
β−, 2n58Ti
61Sc214061.001(600)#2# ms
(>620 ns)		β−61Ti7/2-#
β−, n60Ti
β−, 2n59Ti
62Sc [4] 214162.00785(64)#2# ms
(>400 ns)		β−? [n 8] 62Ti
β−, n? [n 8] 61Ti
β−, 2n? [n 8] 60Ti
This table header & footer:
  1. ↑ mSc – Excited nuclear isomer.
  2. ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. 1 2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ↑ Modes of decay:
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  6. ↑ Bold symbol as daughter – Daughter product is stable.
  7. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  8. 1 2 3 Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.

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References

  1. ↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ↑ "Standard Atomic Weights: Scandium". CIAAW. 2021.
  3. ↑ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN   1365-3075.
  4. ↑ Tarasov, O. B.; et al. (11 July 2018). "Discovery of 60 Ca and Implications For the Stability of 70 Ca". Physical Review Letters. 121 (2): 022501. doi: 10.1103/PhysRevLett.121.022501 . PMID   30085743.
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