Isotopes of scandium

Isotopes of scandium (₂₁Sc)
γ	44Sc
ε	44Ca
γ	–
γ	–
γ	–
Standard atomic weight Ar°(Sc)
	44.955907±0.000004; 44.956±0.001 (abridged);
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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
Nuclide ^{[n 1]}	Excitation energy			Half-life^[1] ^{[n 4]}	Decay mode^[1] ^{[n 5]}	Daughter isotope ^{[n 6]}	Spin and parity^[1] ^{[n 7]}^{[n 4]}	Isotopic abundance
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+
^44m3Sc	271.240(10) keV			58.61(10) h	β⁺ (1.20%)	⁴⁴Ca	6+
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+
^50mSc	256.895(10) keV			350(40) ms	β⁻ (<1%)	⁵⁰Ti	2+
⁵¹Sc	21	30	50.9535688(27)	12.4(1) s	β⁻	⁵¹Ti	(7/2)−
⁵¹Sc	21	30	50.9535688(27)	12.4(1) s	β⁻, n?	⁵⁰Ti	(7/2)−
⁵²Sc	21	31	51.9564962(33)	8.2(2) s	β⁻	⁵²Ti	3(+)
⁵²Sc	21	31	51.9564962(33)	8.2(2) s	β⁻, n?	⁵¹Ti	3(+)
⁵³Sc	21	32	52.958379(19)	2.4(6) s	β⁻	⁵³Ti	(7/2−)
⁵³Sc	21	32	52.958379(19)	2.4(6) s	β⁻, n?	⁵²Ti	(7/2−)
⁵⁴Sc	21	33	53.963029(15)	526(15) ms	β⁻ (84%)	⁵⁴Ti	(3)+
⁵⁴Sc	21	33	53.963029(15)	526(15) ms	β⁻, n (16%)	⁵³Ti	(3)+
^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

^ ^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.
^ Order of ground state and isomer is uncertain.

References

^ ^a ^b ^c ^d 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.
^ 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.
^ ^a ^b 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.

[4] Sc – Excited nuclear isomer.

[6] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-7] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[TNN-8] # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

[9] Modes of decay:

IT: Isomeric transition

n: Neutron emission

p: Proton emission

[10] Bold symbol as daughter – Daughter product is stable.

[11] ( ) spin value – Indicates spin with weak assignment arguments.

[order-13] Order of ground state and isomer is uncertain.

[NUBASE2020-1] 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.

[CIAAW2021-3] 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.

[AME2020_II-5] 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.

[37,38Sc-12] 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.

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