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Standard atomic weight Ar°(Sc) | ||||||||||||||||||||||||||||||||||||||||||||||
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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
[edit]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] |
Isotopic abundance | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy | |||||||||||||||||||
39Sc | 21 | 18 | 38.984790(26) | <300 ns | p | 38Ca | (7/2−)# | ||||||||||||
40Sc | 21 | 19 | 39.977967(3) | 182.3(7) ms | β+ (99.54%) | 40Ca | 4− | ||||||||||||
β+, p (.44%) | 39K | ||||||||||||||||||
β+, α (.017%) | 36Ar | ||||||||||||||||||
41Sc | 21 | 20 | 40.96925113(24) | 596.3(17) ms | β+ | 41Ca | 7/2− | ||||||||||||
42Sc | 21 | 21 | 41.96551643(29) | 681.3(7) ms | β+ | 42Ca | 0+ | ||||||||||||
42mSc | 616.28(6) keV | 61.7(4) s | β+ | 42Ca | (7, 5, 6)+ | ||||||||||||||
43Sc | 21 | 22 | 42.9611507(20) | 3.891(12) h | β+ | 43Ca | 7/2− | ||||||||||||
43m1Sc | 151.4(2) keV | 438(7) μs | 3/2+ | ||||||||||||||||
43m2Sc | 3123.2(3) keV | 470(4) ns | (19/2)− | ||||||||||||||||
44Sc | 21 | 23 | 43.9594028(19) | 3.97(4) h | β+ | 44Ca | 2+ | ||||||||||||
44m1Sc | 67.8680(14) keV | 154.2(8) ns | 1− | ||||||||||||||||
44m2Sc | 270.95(20) keV | 58.61(10) h | IT (98.8%) | 44Sc | 6+ | ||||||||||||||
β+ (1.2%) | 44Ca | ||||||||||||||||||
44m3Sc | 146.224(22) keV | 50.4(7) μs | 0− | ||||||||||||||||
45Sc | 21 | 24 | 44.9559119(9) | Stable | 7/2− | 1.0000 | |||||||||||||
45mSc | 12.40(5) keV | 318(7) ms | IT | 45Sc | 3/2+ | ||||||||||||||
46Sc | 21 | 25 | 45.9551719(9) | 83.79(4) d | β− | 46Ti | 4+ | ||||||||||||
46m1Sc | 52.011(1) keV | 9.4(8) μs | 6+ | ||||||||||||||||
46m2Sc | 142.528(7) keV | 18.75(4) s | IT | 46Sc | 1− | ||||||||||||||
47Sc | 21 | 26 | 46.9524075(22) | 3.3492(6) d | β− | 47Ti | 7/2− | ||||||||||||
47mSc | 766.83(9) keV | 272(8) ns | (3/2)+ | ||||||||||||||||
48Sc | 21 | 27 | 47.952231(6) | 43.67(9) h | β− | 48Ti | 6+ | ||||||||||||
49Sc | 21 | 28 | 48.950024(4) | 57.2(2) min | β− | 49Ti | 7/2− | ||||||||||||
50Sc | 21 | 29 | 49.952188(17) | 102.5(5) s | β− | 50Ti | 5+ | ||||||||||||
50mSc | 256.895(10) keV | 350(40) ms | IT (97.5%) | 50Sc | 2+, 3+ | ||||||||||||||
β− (2.5%) | 50Ti | ||||||||||||||||||
51Sc | 21 | 30 | 50.953603(22) | 12.4(1) s | β− | 51Ti | (7/2)− | ||||||||||||
52Sc | 21 | 31 | 51.95668(21) | 8.2(2) s | β− | 52Ti | 3(+) | ||||||||||||
53Sc | 21 | 32 | 52.95961(32)# | 2.4(0.6) s | β− (>99.9%) | 53Ti | (7/2−)# | ||||||||||||
β−, n (<.1%) | 52Ti | ||||||||||||||||||
54Sc | 21 | 33 | 53.96326(40) | 260(30) ms | β− (>99.9%) | 54Ti | 3+# | ||||||||||||
β−, n (<.1%) | 53Ti | ||||||||||||||||||
54mSc | 110(3) keV | 7(5) μs | (5+) | ||||||||||||||||
55Sc | 21 | 34 | 54.96824(79) | 0.115(15) s | β− (>99.9%) | 55Ti | 7/2−# | ||||||||||||
β−, n (<.1%) | 54Ti | ||||||||||||||||||
56Sc | 21 | 35 | 55.97287(75)# | 35(5) ms | β− | 56Ti | (1+) | ||||||||||||
57Sc | 21 | 36 | 56.97779(75)# | 13(4) ms | β− | 57Ti | 7/2−# | ||||||||||||
58Sc | 21 | 37 | 57.98371(86)# | 12(5) ms | β− | 58Ti | (3+)# | ||||||||||||
59Sc | 21 | 38 | 58.98922(97)# | 10# ms | β−, n | 58Ti | 7/2−# | ||||||||||||
β− | 59Ti | ||||||||||||||||||
60Sc | 21 | 39 | 59.99571(97)# | 3# ms (>620 ns) |
β− | 60Ti | 3+# | ||||||||||||
β−, n | 59Ti | ||||||||||||||||||
β−, 2n | 58Ti | ||||||||||||||||||
61Sc | 21 | 40 | 61.001(600)# | 2# ms (>620 ns) |
β− | 61Ti | 7/2-# | ||||||||||||
β−, n | 60Ti | ||||||||||||||||||
β−, 2n | 59Ti | ||||||||||||||||||
62Sc[4] | 21 | 41 | 62.00785(64)# | 2# ms (>400 ns) |
β−?[n 8] | 62Ti | |||||||||||||
β−, n?[n 8] | 61Ti | ||||||||||||||||||
β−, 2n?[n 8] | 60Ti | ||||||||||||||||||
This table header & footer: |
- ^ mSc – Excited nuclear isomer.
- ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- ^ a b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- ^
Modes of decay:
IT: Isomeric transition n: Neutron emission p: Proton emission - ^ Bold symbol as daughter – Daughter product is stable.
- ^ ( ) spin value – Indicates spin with weak assignment arguments.
- ^ a b c Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide.
References
[edit]- ^ 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.
- ^ "Standard Atomic Weights: Scandium". CIAAW. 2021.
- ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (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.
- ^ 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.
- Audi, G.; Kondev, F.G.; Wang, M.; Huang, W.J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. doi:10.1088/1674-1137/41/3/030001.
- Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
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