Isotopes of scandium

Isotopes of scandium  (₂₁Sc)

Main isotopes [1] Decay abun­dance half-life (t1/2) mode pro­duct 44Sc synth 4.0421 h ε 44Ca 44m3Sc synth 58.61 h IT 44Sc γ 44Sc ε 44Ca 45Sc 100% stable 46Sc synth 83.757 d β− 46Ti γ – 47Sc synth 3.3492 d β− 47Ti γ – 48Sc synth 43.67 h β− 48Ti γ –
Standard atomic weight Ar°(Sc)
	44.955907±0.000004 [2] 44.956±0.001 (abridged) [3]
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Naturally occurring scandium (₂₁Sc) is composed of one stable isotope, ⁴⁵Sc. Twenty-seven 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 (t_1/2 58.6 h).

The isotopes of scandium range from ³⁷Sc to 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) [4] [n 2] [n 3]	Half-life [1] [n 4]	Decay mode [1] [n 5]	Daughter isotope [n 6]	Spin and parity [1] [n 7] [n 4]	Isotopic abundance
	Excitation energy
37Sc [5]	21	16	37.00376(44)		p	36Ca
38Sc [5]	21	17	37.995002(15)		p	37Ca
39Sc	21	18	38.984785(26)		p	38Ca	7/2−#
40Sc	21	19	39.9779673(30)	182.3(7) ms	β+ (99.54%)	40Ca	4−
					β+, p (0.44%)	39K
					β+, α (0.017%)	36Ar
41Sc	21	20	40.969251163(83)	596.3(17) ms	β+	41Ca	7/2−
42Sc	21	21	41.96551669(17)	680.72(26) ms	β+	42Ca	0+
42mSc	616.81(6) keV			61.7(4) s	β+	42Ca	7+
43Sc	21	22	42.9611504(20)	3.891(12) h	β+	43Ca	7/2−
43m1Sc	151.79(8) keV			438(5) μs	IT	43Sc	3/2+
43m2Sc	3123.73(15) keV			472(3) ns	IT	43Sc	19/2−
44Sc	21	23	43.9594028(19)	4.0421(25) h	β+	44Ca	2+
44m1Sc	67.8679(14) keV			154.8(8) ns	IT	44Sc	1−
44m2Sc	146.1914(20) keV			51.0(3) μs	IT	44Sc	0−
44m3Sc	271.240(10) keV			58.61(10) h	IT (98.80%)	44Sc	6+
					β+ (1.20%)	44Ca
45Sc	21	24	44.95590705(71)	Stable			7/2−	1.0000
45mSc	12.40(5) keV			318(7) ms	IT	45Sc	3/2+
46Sc	21	25	45.95516703(72)	83.757(14) d	β−	46Ti	4+
46m1Sc	52.011(1) keV			9.4(8) μs	IT	46Sc	6+
46m2Sc	142.528(7) keV			18.75(4) s	IT	46Sc	1−
47Sc	21	26	46.9524024(21)	3.3492(6) d	β−	47Ti	7/2−
47mSc	766.83(9) keV			272(8) ns	IT	47Sc	(3/2)+
48Sc	21	27	47.9522229(53)	43.67(9) h	β−	48Ti	6+
49Sc	21	28	48.9500132(24)	57.18(13) min	β−	49Ti	7/2−
50Sc	21	29	49.9521874(27)	102.5(5) s	β−	50Ti	5+
50mSc	256.895(10) keV			350(40) ms	IT (>99%)	50Sc	2+
					β− (<1%)	50Ti
51Sc	21	30	50.9535688(27)	12.4(1) s	β−	51Ti	(7/2)−
					β−, n?	50Ti
52Sc	21	31	51.9564962(33)	8.2(2) s	β−	52Ti	3(+)
					β−, n?	51Ti
53Sc	21	32	52.958379(19)	2.4(6) s	β−	53Ti	(7/2−)
					β−, n?	52Ti
54Sc	21	33	53.963029(15)	526(15) ms	β− (84%)	54Ti	(3)+
					β−, n (16%)	53Ti
54mSc	110.5(3) keV			2.77(2) μs	IT	54Sc	(5+,4+)
55Sc	21	34	54.966890(67)	96(2) ms	β− (83%)	55Ti	(7/2)−
					β−, n (17%)	54Ti
					β−, 2n?	53Ti
56Sc	21	35	55.97261(28)	26(6) ms	β−	56Ti	(1+)
					β−, n?	55Ti
					β−, 2n?	54Ti
56m1Sc [n 8]	0(100)# keV			75(6) ms	β− (<88%)	56Ti	(6+,5+)
					β−, n (>12%)	55Ti
					β−, 2n?	54Ti
56m2Sc	775.0(1) keV			290(17) ns	IT	56Sc	(4+)
57Sc	21	36	56.97705(19)	22(2) ms	β−	57Ti	7/2−#
					β−, n?	56Ti
					β−, 2n?	55Ti
58Sc	21	37	57.98338(20)	12(5) ms	β−	58Ti	3+#
					β−, n?	57Ti
					β−, 2n?	56Ti
58mSc	1420.7(22) keV			0.60(13) μs	IT	58Sc
59Sc	21	38	58.98837(27)	12# ms [>620 ns]	β−?	59Ti	7/2−#
					β−, n?	58Ti
					β−, 2n?	57Ti
60Sc	21	39	59.99512(54)#	10# ms [>620 ns]	β−?	60Ti	3+#
					β−, n?	59Ti
					β−, 2n?	58Ti
61Sc	21	40	61.00054(64)#	7# ms [>620 ns]	β−?	61Ti	7/2-#
					β−, n?	60Ti
					β−, 2n?	59Ti
62Sc	21	41	62.00785(64)#	2# ms [>400 ns]	β−?	62Ti
					β−, n?	61Ti
					β−, 2n?	60Ti
This table header & footer: view

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. # – 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. Order of ground state and isomer is uncertain.

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; 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.
4. Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
5. Dronchi, N.; Charity, R. J.; Sobotka, L. G.; Brown, B. A.; Weisshaar, D.; Gade, A.; Brown, K. W.; Reviol, W.; Bazin, D.; Farris, P. J.; Hill, A. M.; Li, J.; Longfellow, B.; Rhodes, D.; Paneru, S. N.; Gillespie, S. A.; Anthony, A. K.; Rubino, E.; Biswas, S. (2024-09-12). "Evolution of shell gaps in the neutron-poor calcium region from invariant-mass spectroscopy of ^37,38Sc, ³⁵Ca, and ³⁴K". Physical Review C. 110 (3). doi:10.1103/PhysRevC.110.L031302. ISSN   2469-9985.

• 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.