Isotopes of scandium

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Naturally occurring scandium (Sc) is composed of 1 stable isotope ⁴⁵Sc. 13 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. All of the remaining radioactive isotopes have half lives that are less than 4 hours, and the majority of these have half-lives that are less than 2 minutes. This element also has 100 meta states with the most stable being ^44mSc (t_½ 58.6 h).

The isotopes of scandium range in atomic weight from 40 u (⁴⁰Sc) to 54 u (⁵⁴Sc). The primary decay mode at masses lower than the only stable isotope, ⁴⁵Sc, is electron capture, and the primary mode at masses above it is beta emission. The primary decay products at atomic weights below ⁴⁵Sc are calcium isotopes and the primary products from higher atomic weights are titanium isotopes.

Standard atomic mass: 44.955912(6) u

[edit] Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
³⁶Sc	21	15	36.01492(54)#
³⁷Sc	21	16	37.00305(32)#		7/2-#
³⁸Sc	21	17	37.99470(32)#	<300 ns	(2-)#
³⁹Sc	21	18	38.984790(26)	<300 ns	(7/2-)#
⁴⁰Sc	21	19	39.977967(3)	182.3(7) ms	4-
⁴¹Sc	21	20	40.96925113(24)	596.3(17) ms	7/2-
⁴²Sc	21	21	41.96551643(29)	681.3(7) ms	0+
^42mSc	616.28(6) keV			61.7(4) s	(7,5,6)+
⁴³Sc	21	22	42.9611507(20)	3.891(12) h	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	2+
^44m1Sc	67.8680(14) keV			154.2(8) ns	1-
^44m2Sc	270.95(20) keV			58.61(10) h	6+
^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	3/2+
⁴⁶Sc	21	25	45.9551719(9)	83.79(4) d	4+
^46m1Sc	52.011(1) keV			9.4(8) µs	6+
^46m2Sc	142.528(7) keV			18.75(4) s	1-
⁴⁷Sc	21	26	46.9524075(22)	3.3492(6) d	7/2-
^47mSc	766.83(9) keV			272(8) ns	(3/2)+
⁴⁸Sc	21	27	47.952231(6)	43.67(9) h	6+
⁴⁹Sc	21	28	48.950024(4)	57.2(2) min	7/2-
⁵⁰Sc	21	29	49.952188(17)	102.5(5) s	5+
^50mSc	256.895(10) keV			350(40) ms	2+,3+
⁵¹Sc	21	30	50.953603(22)	12.4(1) s	(7/2)-
⁵²Sc	21	31	51.95668(21)	8.2(2) s	3(+)
⁵³Sc	21	32	52.95961(32)#	>3 s	(7/2-)#
⁵⁴Sc	21	33	53.96326(40)	260(30) ms	3+#
^54mSc	110(3) keV			7(5) µs	(5+)
⁵⁵Sc	21	34	54.96824(79)	0.115(15) s	7/2-#
⁵⁶Sc	21	35	55.97287(75)#	35(5) ms	(1+)
⁵⁷Sc	21	36	56.97779(75)#	13(4) ms	7/2-#
⁵⁸Sc	21	37	57.98371(86)#	12(5) ms	(3+)#
⁵⁹Sc	21	38	58.98922(97)#	10# ms	7/2-#
⁶⁰Sc	21	39	59.99571(97)#	3# ms	3+#

[edit] 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.

[edit] References

Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.