Isotopes of scandium
Encyclopedia
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. 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 (t½ 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 product
s 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
Scandium
Scandium is a chemical element with symbol Sc and atomic number 21. A silvery-white metallic transition metal, it has historically been sometimes classified as a rare earth element, together with yttrium and the lanthanoids...
(Sc) is composed of one stable isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
45Sc. Twenty-four radioisotopes have been characterized with the most stable being 46Sc with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
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 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 (t½ 58.6 h).
The isotopes of scandium range in atomic weight
Atomic weight
Atomic weight is a dimensionless physical quantity, the ratio of the average mass of atoms of an element to 1/12 of the mass of an atom of carbon-12...
from 36 u
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
(36Sc) to 60 u (60Sc). The primary decay mode at masses lower than the only stable isotope, 45Sc, is Beta-plus
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...
or electron capture
Electron capture
Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...
, and the primary mode at masses above it is beta-minus. The primary decay product
Decay product
In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...
s at atomic weights below 45Sc are calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
isotopes and the primary products from higher atomic weights are titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
isotopes.
Standard atomic mass: 44.955912(6) u
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-life | decay mode(s)Abbreviations: IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
daughter isotope(s)Bold for stable isotopes |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 36Sc | 21 | 15 | 36.01492(54)# | p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... |
35Ca | ||||
| 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+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... (99.54%) |
40Ca | 4- | ||
| β+, p (.44%) | 39K | ||||||||
| β+, α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... (.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 Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... (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 Neutron emission Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13... (<.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+# | ||||