Naturally occurring

scandium Scandium is a chemical element with the symbol Sc and atomic number 21. It is a silvery-white metallic d-block element. Historically, it has been classified as a rare-earth element, together with yttrium and the Lanthanides. It was discovered in ...

(₂₁Sc) is composed of one stable

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...

, ⁴⁵Sc. Twenty-five

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

s have been characterized, with the most stable being ⁴⁶Sc with a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...

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 state A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ha ...

s with the most stable being ^44m2Sc (t_1/2 58.6 h). The isotopes of scandium range in

atomic weight Relative atomic mass (symbol: ''A''; sometimes abbreviated RAM or r.a.m.), also known by the deprecated synonym atomic weight, is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a giv ...

from 38 u (³⁶Sc) to 62 u (⁶²Sc). The primary

decay mode Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

at masses lower than the only stable isotope, ⁴⁵Sc, is beta-plus or

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Thi ...

, and the primary mode at masses above it is beta-minus. The primary

decay product In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps ( ...

s at atomic weights below ⁴⁵Sc are calcium isotopes and the primary products from higher atomic weights are

titanium isotopes Naturally occurring titanium (22Ti) is composed of five stable isotopes; 46Ti, 47Ti, 48Ti, 49Ti and 50Ti with 48Ti being the most abundant (73.8% natural abundance). Twenty-one radioisotopes have been characterized, with the most stable being 44Ti ...

List of isotopes

, - , ³⁹Sc , style="text-align:right" , 21 , style="text-align:right" , 18 , 38.984790(26) , <300 ns , p , ³⁸Ca , (7/2−)# , , , - , rowspan=3, ⁴⁰Sc , rowspan=3 style="text-align:right" , 21 , rowspan=3 style="text-align:right" , 19 , rowspan=3, 39.977967(3) , rowspan=3, 182.3(7) ms , β⁺ (99.54%) , ⁴⁰Ca , rowspan=3, 4- , rowspan=3, , rowspan=3, , - , β⁺, p (.44%) , ³⁹K , - , β⁺, α (.017%) , ³⁶Ar , - , ⁴¹Sc , style="text-align:right" , 21 , style="text-align:right" , 20 , 40.96925113(24) , 596.3(17) ms , β⁺ , ⁴¹Ca , 7/2− , , , - , ⁴²Sc , style="text-align:right" , 21 , style="text-align:right" , 21 , 41.96551643(29) , 681.3(7) ms , β⁺ , ⁴²Ca , 0+ , , , - , style="text-indent:1em" , ^42mSc , colspan="3" style="text-indent:2em" , 616.28(6) keV , 61.7(4) s , β⁺ , ⁴²Ca , (7, 5, 6)+ , , , - , ⁴³Sc , style="text-align:right" , 21 , style="text-align:right" , 22 , 42.9611507(20) , 3.891(12) h , β⁺ , ⁴³Ca , 7/2− , , , - , style="text-indent:1em" , ^43m1Sc , colspan="3" style="text-indent:2em" , 151.4(2) keV , 438(7) μs , , , 3/2+ , , , - , style="text-indent:1em" , ^43m2Sc , colspan="3" style="text-indent:2em" , 3123.2(3) keV , 470(4) ns , , , (19/2)− , , , - , ⁴⁴Sc , style="text-align:right" , 21 , style="text-align:right" , 23 , 43.9594028(19) , 3.97(4) h , β⁺ , ⁴⁴Ca , 2+ , , , - , style="text-indent:1em" , ^44m1Sc , colspan="3" style="text-indent:2em" , 67.8680(14) keV , 154.2(8) ns , , , 1− , , , - , rowspan=2 style="text-indent:1em" , ^44m2Sc , rowspan=2 colspan="3" style="text-indent:2em" , 270.95(20) keV , rowspan=2, 58.61(10) h , IT (98.8%) , ⁴⁴Sc , rowspan=2, 6+ , rowspan=2, , rowspan=2, , - , β⁺ (1.2%) , ⁴⁴Ca , - , style="text-indent:1em" , ^44m3Sc , colspan="3" style="text-indent:2em" , 146.224(22) keV , 50.4(7) μs , , , 0- , , , - , ⁴⁵Sc , style="text-align:right" , 21 , style="text-align:right" , 24 , 44.9559119(9) , colspan=3 align=center, Stable , 7/2− , 1.0000 , , - , style="text-indent:1em" , ^45mSc , colspan="3" style="text-indent:2em" , 12.40(5) keV , 318(7) ms , IT , ⁴⁵Sc , 3/2+ , , , - , ⁴⁶Sc , style="text-align:right" , 21 , style="text-align:right" , 25 , 45.9551719(9) , 83.79(4) d , β⁻ , ⁴⁶Ti , 4+ , , , - , style="text-indent:1em" , ^46m1Sc , colspan="3" style="text-indent:2em" , 52.011(1) keV , 9.4(8) μs , , , 6+ , , , - , style="text-indent:1em" , ^46m2Sc , colspan="3" style="text-indent:2em" , 142.528(7) keV , 18.75(4) s , IT , ⁴⁶Sc , 1− , , , - , ⁴⁷Sc , style="text-align:right" , 21 , style="text-align:right" , 26 , 46.9524075(22) , 3.3492(6) d , β⁻ , ⁴⁷Ti , 7/2− , , , - , style="text-indent:1em" , ^47mSc , colspan="3" style="text-indent:2em" , 766.83(9) keV , 272(8) ns , , , (3/2)+ , , , - , ⁴⁸Sc , style="text-align:right" , 21 , style="text-align:right" , 27 , 47.952231(6) , 43.67(9) h , β⁻ , ⁴⁸Ti , 6+ , , , - , ⁴⁹Sc , style="text-align:right" , 21 , style="text-align:right" , 28 , 48.950024(4) , 57.2(2) min , β⁻ , ⁴⁹Ti , 7/2− , , , - , ⁵⁰Sc , style="text-align:right" , 21 , style="text-align:right" , 29 , 49.952188(17) , 102.5(5) s , β⁻ , ⁵⁰Ti , 5+ , , , - , rowspan=2 style="text-indent:1em" , ^50mSc , rowspan=2 colspan="3" style="text-indent:2em" , 256.895(10) keV , rowspan=2, 350(40) ms , IT (97.5%) , ⁵⁰Sc , rowspan=2, 2+, 3+ , rowspan=2, , rowspan=2, , - , β⁻ (2.5%) , ⁵⁰Ti , - , ⁵¹Sc , style="text-align:right" , 21 , style="text-align:right" , 30 , 50.953603(22) , 12.4(1) s , β⁻ , ⁵¹Ti , (7/2)− , , , - , ⁵²Sc , style="text-align:right" , 21 , style="text-align:right" , 31 , 51.95668(21) , 8.2(2) s , β⁻ , ⁵²Ti , 3(+) , , , - , rowspan=2, ⁵³Sc , rowspan=2 style="text-align:right" , 21 , rowspan=2 style="text-align:right" , 32 , rowspan=2, 52.95961(32)# , rowspan=2, 2.4(0.6) s , β⁻ (>99.9%) , ⁵³Ti , rowspan=2, (7/2−)# , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁵²Ti , - , rowspan=2, ⁵⁴Sc , rowspan=2 style="text-align:right" , 21 , rowspan=2 style="text-align:right" , 33 , rowspan=2, 53.96326(40) , rowspan=2, 260(30) ms , β⁻ (>99.9%) , ⁵⁴Ti , rowspan=2, 3+# , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁵³Ti , - , style="text-indent:1em" , ^54mSc , colspan="3" style="text-indent:2em" , 110(3) keV , 7(5) μs , , , (5+) , , , - , rowspan=2, ⁵⁵Sc , rowspan=2 style="text-align:right" , 21 , rowspan=2 style="text-align:right" , 34 , rowspan=2, 54.96824(79) , rowspan=2, 0.115(15) s , β⁻ (>99.9%) , ⁵⁵Ti , rowspan=2, 7/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁵⁴Ti , - , ⁵⁶Sc , style="text-align:right" , 21 , style="text-align:right" , 35 , 55.97287(75)# , 35(5) ms , β⁻ , ⁵⁶Ti , (1+) , , , - , ⁵⁷Sc , style="text-align:right" , 21 , style="text-align:right" , 36 , 56.97779(75)# , 13(4) ms , β⁻ , ⁵⁷Ti , 7/2−# , , , - , ⁵⁸Sc , style="text-align:right" , 21 , style="text-align:right" , 37 , 57.98371(86)# , 12(5) ms , β⁻ , ⁵⁸Ti , (3+)# , , , - , rowspan=2, ⁵⁹Sc , rowspan=2 style="text-align:right" , 21 , rowspan=2 style="text-align:right" , 38 , rowspan=2, 58.98922(97)# , rowspan=2, 10# ms , β⁻, n , ⁵⁸Ti , rowspan=2, 7/2−# , rowspan=2, , rowspan=2, , - , β⁻ , ⁵⁹Ti , - , rowspan=3, ⁶⁰Sc , rowspan=3 style="text-align:right" , 21 , rowspan=3 style="text-align:right" , 39 , rowspan=3, 59.99571(97)# , rowspan=3, 3# ms
(>620 ns) , β⁻ , ⁶⁰Ti , rowspan=3, 3+# , rowspan=3, , rowspan=3, , - , β⁻, n , ⁵⁹Ti , - , β⁻, 2n , ⁵⁸Ti , - , rowspan=3, ⁶¹Sc , rowspan=3 style="text-align:right" , 21 , rowspan=3 style="text-align:right" , 40 , rowspan=3, 61.001(600)# , rowspan=3, 2# ms
(>620 ns) , β⁻ , ⁶¹Ti , rowspan=3, 7/2-# , rowspan=3, , rowspan=3, , - , β⁻, n , ⁶⁰Ti , - , β⁻, 2n , ⁵⁹Ti

References

* * Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Scandium

Scandium Scandium is a chemical element with the symbol Sc and atomic number 21. It is a silvery-white metallic d-block element. Historically, it has been classified as a rare-earth element, together with yttrium and the Lanthanides. It was discovered in ...