Isotopes of scandium

Naturally occurring scandium (Sc) is composed of one stable isotope ⁴⁵Sc. Twenty-four 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 Sc-44 with a half-life of 3.97 hours. All of the remaining radioactive 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 ³⁹Sc with a half-life shorter than 300 nanoseconds. The half-lives for isotopes with mass numbers less than 39 is unknown. This element also has 10 meta states with the most stable being ^44mSc (t_1/2 58.6 h).

The isotopes of scandium range in atomic weight from 36 u (³⁶Sc) to 60 u (⁶⁰Sc). 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.

Relative atomic mass: 44.955912(6).

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)[1]	daughter isotope(s)[n 1]	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
^37Sc	21	16	37.00305(32)#		p	^36Ca	7/2−#
^38Sc	21	17	37.99470(32)#	<300 ns	p	^37Ca	(2−)#
^38mSc					p	^37Ca
^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)#	>3 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			3+#

1. Bold for stable isotopes, bold italic for nearly-stable isotopes (half-life longer than the age of the universe)

Notes

• Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
• Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.
• Nuclide masses are given by IUPAP Commission on Symbols, Units, Nomenclature, Atomic Masses and Fundamental Constants (SUNAMCO)
• Isotope abundances are given by IUPAC Commission on Isotopic Abundances and Atomic Weights

References

1. "Universal Nuclide Chart". nucleonica. (registration required (help)).

• Isotope masses from:
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
• Isotopic compositions and standard atomic masses from:
  • J. R. de Laeter; J. K. Böhlke; P. De Bièvre; H. Hidaka; H. S. Peiser; K. J. R. Rosman; P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683.
  • M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
• Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
  • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
  • N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.