Isotopes of scandium

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Main isotopes of scandium (21Sc)
Iso­tope Decay
abun­dance half-life (t1/2) mode pro­duct
44m2Sc syn 58.61 h IT 44Sc
γ 44Sc
ε 44Ca
45Sc 100% stable
46Sc syn 83.79 d β 46Ti
γ
47Sc syn 80.38 h β 47Ti
γ
48Sc syn 43.67 h β 48Ti
γ
Standard atomic weight Ar, standard(Sc)
  • 44.955908(5)[1]

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 38 u (36Sc) 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 (u)
[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 energy Normal proportion Range of variation
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
  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. ^ a b # – 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.

References[edit]

  1. ^ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.