Naturally occurring

titanium Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

(₂₂Ti) is composed of five 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) ...

s; ⁴⁶Ti, ⁴⁷Ti, ⁴⁸Ti, ⁴⁹Ti and ⁵⁰Ti with ⁴⁸Ti being the most abundant (73.8%

natural abundance In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the atomic ...

). Twenty-one

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 ⁴⁴Ti 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 60 years, ⁴⁵Ti with a half-life of 184.8 minutes, ⁵¹Ti with a half-life of 5.76 minutes, and ⁵²Ti with a half-life of 1.7 minutes. All of the remaining

radioactive 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 ...

isotopes have half-lives that are less than 33 seconds, and the majority of these have half-lives that are less than half a second. The isotopes of titanium range in

atomic mass The atomic mass (''m''a or ''m'') is the mass of an atom. Although the SI unit of mass is the kilogram (symbol: kg), atomic mass is often expressed in the non-SI unit dalton (symbol: Da) – equivalently, unified atomic mass unit (u). 1&nbs ...

from 38.01 u (³⁸Ti) to 62.99 u (⁶³Ti). 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 ...

for isotopes lighter than the stable isotopes (lighter than ⁴⁶Ti) is β⁺ and the primary mode for the heavier ones (heavier than ⁵⁰Ti) is β⁻; their respective

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 are scandium isotopes and the primary products after are vanadium isotopes.

List of isotopes

, - , rowspan=3, ³⁹Ti , rowspan=3 style="text-align:right" , 22 , rowspan=3 style="text-align:right" , 17 , rowspan=3, 39.00161(22)# , rowspan=3, 31(4) ms
1(+6-4) ms, β⁺, p (85%) , ³⁸Ca , rowspan=3, 3/2+# , rowspan=3, , rowspan=3, , - , β⁺ (15%) , ³⁹Sc , - , β⁺, 2p (<.1%) , ³⁷K , - , rowspan=2, ⁴⁰Ti , rowspan=2 style="text-align:right" , 22 , rowspan=2 style="text-align:right" , 18 , rowspan=2, 39.99050(17) , rowspan=2, 53.3(15) ms , β⁺ (56.99%) , ⁴⁰Sc , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺, p (43.01%) , ³⁹Ca , - , rowspan=2, ⁴¹Ti , rowspan=2 style="text-align:right" , 22 , rowspan=2 style="text-align:right" , 19 , rowspan=2, 40.98315(11)# , rowspan=2, 80.4(9) ms , β⁺, p (>99.9%) , ⁴⁰Ca , rowspan=2, 3/2+ , rowspan=2, , rowspan=2, , - , β⁺ (<.1%) , ⁴¹Sc , - , ⁴²Ti , style="text-align:right" , 22 , style="text-align:right" , 20 , 41.973031(6) , 199(6) ms , β⁺ , ⁴²Sc , 0+ , , , - , ⁴³Ti , style="text-align:right" , 22 , style="text-align:right" , 21 , 42.968522(7) , 509(5) ms , β⁺ , ⁴³Sc , 7/2− , , , - , style="text-indent:1em" , ^43m1Ti , colspan="3" style="text-indent:2em" , 313.0(10) keV , 12.6(6) μs , , , (3/2+) , , , - , style="text-indent:1em" , ^43m2Ti , colspan="3" style="text-indent:2em" , 3066.4(10) keV , 560(6) ns , , , (19/2−) , , , - , ⁴⁴Ti , style="text-align:right" , 22 , style="text-align:right" , 22 , 43.9596901(8) , 60.0(11) y , EC , ⁴⁴Sc , 0+ , , , - , ⁴⁵Ti , style="text-align:right" , 22 , style="text-align:right" , 23 , 44.9581256(11) , 184.8(5) min , β⁺ , ⁴⁵Sc , 7/2− , , , - , ⁴⁶Ti , style="text-align:right" , 22 , style="text-align:right" , 24 , 45.9526316(9) , colspan=3 align=center, Stable , 0+ , 0.0825(3) , , - , ⁴⁷Ti , style="text-align:right" , 22 , style="text-align:right" , 25 , 46.9517631(9) , colspan=3 align=center, Stable , 5/2− , 0.0744(2) , , - , ⁴⁸Ti , style="text-align:right" , 22 , style="text-align:right" , 26 , 47.9479463(9) , colspan=3 align=center, Stable , 0+ , 0.7372(3) , , - , ⁴⁹Ti , style="text-align:right" , 22 , style="text-align:right" , 27 , 48.9478700(9) , colspan=3 align=center, Stable , 7/2− , 0.0541(2) , , - , ⁵⁰Ti , style="text-align:right" , 22 , style="text-align:right" , 28 , 49.9447912(9) , colspan=3 align=center, Stable , 0+ , 0.0518(2) , , - , ⁵¹Ti , style="text-align:right" , 22 , style="text-align:right" , 29 , 50.946615(1) , 5.76(1) min , β⁻ , ⁵¹V , 3/2− , , , - , ⁵²Ti , style="text-align:right" , 22 , style="text-align:right" , 30 , 51.946897(8) , 1.7(1) min , β⁻ , ⁵²V , 0+ , , , - , ⁵³Ti , style="text-align:right" , 22 , style="text-align:right" , 31 , 52.94973(11) , 32.7(9) s , β⁻ , ⁵³V , (3/2)− , , , - , ⁵⁴Ti , style="text-align:right" , 22 , style="text-align:right" , 32 , 53.95105(13) , 1.5(4) s , β⁻ , ⁵⁴V , 0+ , , , - , ⁵⁵Ti , style="text-align:right" , 22 , style="text-align:right" , 33 , 54.95527(16) , 490(90) ms , β⁻ , ⁵⁵V , 3/2−# , , , - , rowspan=2, ⁵⁶Ti , rowspan=2 style="text-align:right" , 22 , rowspan=2 style="text-align:right" , 34 , rowspan=2, 55.95820(21) , rowspan=2, 164(24) ms , β⁻ (>99.9%) , ⁵⁶V , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁵⁵V , - , rowspan=2, ⁵⁷Ti , rowspan=2 style="text-align:right" , 22 , rowspan=2 style="text-align:right" , 35 , rowspan=2, 56.96399(49) , rowspan=2, 60(16) ms , β⁻ (>99.9%) , ⁵⁷V , rowspan=2, 5/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁵⁶V , - , ⁵⁸Ti , style="text-align:right" , 22 , style="text-align:right" , 36 , 57.96697(75)# , 54(7) ms , β⁻ , ⁵⁸V , 0+ , , , - , ⁵⁹Ti , style="text-align:right" , 22 , style="text-align:right" , 37 , 58.97293(75)# , 30(3) ms , β⁻ , ⁵⁹V , (5/2−)# , , , - , ⁶⁰Ti , style="text-align:right" , 22 , style="text-align:right" , 38 , 59.97676(86)# , 22(2) ms , β⁻ , ⁶⁰V , 0+ , , , - , rowspan=2, ⁶¹Ti , rowspan=2 style="text-align:right" , 22 , rowspan=2 style="text-align:right" , 39 , rowspan=2, 60.98320(97)# , rowspan=2, 10# ms
300 ns, β⁻ , ⁶¹V , rowspan=2, 1/2−# , rowspan=2, , rowspan=2, , - , β⁻, n , ⁶⁰V , - , ⁶²Ti , style="text-align:right" , 22 , style="text-align:right" , 40 , 61.98749(97)# , 10# ms , , , 0+ , , , - , ⁶³Ti , style="text-align:right" , 22 , style="text-align:right" , 41 , 62.99442(107)# , 3# ms , , , 1/2−# , , , - , ⁶⁴Ti , style="text-align:right" , 22 , style="text-align:right" , 42 , 63.998410(640)# , 5# ms
620 ns, , , 0+ , ,

Titanium-44

Titanium-44 (⁴⁴Ti) is a radioactive isotope of titanium that undergoes

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 ...

to an

excited state In quantum mechanics, an excited state of a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state (that is, more energy than the absolute minimum). Excitation refers to a ...

scandium-44 Scandium-44 (44Sc) is a radioactive isotope of scandium that decays by positron emission to stable 44Ca with a half-life of 4.042 hours. 44Sc can be obtained as a daughter radionuclide of long-lived 44Ti (t1/2 60.4 a) from 44Ti /44Sc generator ...

with a half-life of 60 years, before the ground state of ⁴⁴Sc and ultimately ⁴⁴Ca are populated. Because titanium-44 can only undergo electron capture, its half-life increases with ionization and it becomes stable in its fully ionized state (that is, having a charge of +22). Titanium-44 is produced in relative abundance in the

alpha process The alpha process, also known as the alpha ladder, is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements, the other being the triple-alpha process. The triple-alpha process consumes only helium, an ...

stellar nucleosynthesis Stellar nucleosynthesis is the creation (nucleosynthesis) of chemical elements by nuclear fusion reactions within stars. Stellar nucleosynthesis has occurred since the original creation of hydrogen, helium and lithium during the Big Bang. As a ...

and the early stages of

supernova A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when ...

explosions. It is produced when

calcium-40 Calcium (20Ca) has 26 known isotopes, ranging from 35Ca to 60Ca. There are five stable isotopes (40Ca, 42Ca, 43Ca, 44Ca and 46Ca), plus one isotope ( 48Ca) with such a long half-life that for all practical purposes it can be considered stable. T ...

fuses with an

alpha particle Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produce ...

(

helium-4 Helium-4 () is a stable isotope of the element helium. It is by far the more abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on Earth. Its nucleus is identical to an alpha particle, and consis ...

nucleus) in a star's high-temperature environment; the resulting ⁴⁴Ti nucleus can then fuse with another alpha particle to form chromium-48. The age of supernovae may be determined through measurements of

gamma-ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nucleus, atomic nuclei. It consists of the shortest wavelength electromagnetic wav ...

emissions from titanium-44 and its abundance. It was observed in the

Cassiopeia A Cassiopeia A (Cas A) () is a supernova remnant (SNR) in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies above 1 GHz. The supernova occurred approximately away within the Milky Way ...

supernova remnant and

SN 1987A SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately from Earth and was the closest observed supernova since Kepler's Supernova. 1987A's light reached Earth on Feb ...

at a relatively high concentration, a consequence of delayed decay resulting from ionizing conditions.

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 Titanium Titaniun