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 with a half-life 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 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.[4]
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| Standard atomic weight Ar°(Ti) | |||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
The isotopes of titanium range in atomic mass from 39.00 u (39Ti) to 64.00 u (64Ti). The primary decay mode 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 products are scandium isotopes and the primary products after are vanadium isotopes.[4]
List of isotopes
edit
| Nuclide [n 1] |
Z | N | Isotopic mass (Da)[5] [n 2][n 3] |
Half-life[1] [n 4] |
Decay mode[1] [n 5] |
Daughter isotope [n 6] |
Spin and parity[1] [n 7][n 4] |
Natural abundance (mole fraction) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Excitation energy | Normal proportion[1] | Range of variation | |||||||||||||||||
| 39Ti | 22 | 17 | 39.00268(22)# | 28.5(9) ms | β+, p (93.7%) | 38Ca | 3/2+# | ||||||||||||
| β+ (~6.3%) | 39Sc | ||||||||||||||||||
| β+, 2p (?%) | 37K | ||||||||||||||||||
| 40Ti | 22 | 18 | 39.990345(73) | 52.4(3) ms | β+, p (95.8%) | 39Ca | 0+ | ||||||||||||
| β+ (4.2%) | 40Sc | ||||||||||||||||||
| 41Ti | 22 | 19 | 40.983148(30) | 81.9(5) ms | β+, p (91.1%) | 40Ca | 3/2+ | ||||||||||||
| β+ (8.9%) | 41Sc | ||||||||||||||||||
| 42Ti | 22 | 20 | 41.97304937(29) | 208.3(4) ms | β+ | 42Sc | 0+ | ||||||||||||
| 43Ti | 22 | 21 | 42.9685284(61) | 509(5) ms | β+ | 43Sc | 7/2− | ||||||||||||
| 43m1Ti | 313.0(10) keV | 11.9(3) μs | IT | 43Ti | (3/2+) | ||||||||||||||
| 43m2Ti | 3066.4(10) keV | 556(6) ns | IT | 43Ti | (19/2−) | ||||||||||||||
| 44Ti | 22 | 22 | 43.95968994(75) | 59.1(3) y | EC | 44Sc | 0+ | ||||||||||||
| 45Ti | 22 | 23 | 44.95812076(90) | 184.8(5) min | β+ | 45Sc | 7/2− | ||||||||||||
| 45mTi | 36.53(15) keV | 3.0(2) μs | IT | 45Ti | 3/2− | ||||||||||||||
| 46Ti | 22 | 24 | 45.952626356(97) | Stable | 0+ | 0.0825(3) | |||||||||||||
| 47Ti | 22 | 25 | 46.951757491(85) | Stable | 5/2− | 0.0744(2) | |||||||||||||
| 48Ti | 22 | 26 | 47.947940677(79) | Stable | 0+ | 0.7372(3) | |||||||||||||
| 49Ti | 22 | 27 | 48.947864391(84) | Stable | 7/2− | 0.0541(2) | |||||||||||||
| 50Ti | 22 | 28 | 49.944785.622(88) | Stable | 0+ | 0.0518(2) | |||||||||||||
| 51Ti | 22 | 29 | 50.94660947(52) | 5.76(1) min | β− | 51V | 3/2− | ||||||||||||
| 52Ti | 22 | 30 | 51.9468835(29) | 1.7(1) min | β− | 52V | 0+ | ||||||||||||
| 53Ti | 22 | 31 | 52.9496707(31) | 32.7(9) s | β− | 53V | (3/2)− | ||||||||||||
| 54Ti | 22 | 32 | 53.950892(17) | 2.1(10) s | β− | 54V | 0+ | ||||||||||||
| 55Ti | 22 | 33 | 54.955091(31) | 1.3(1) s | β− | 55V | (1/2)− | ||||||||||||
| 56Ti | 22 | 34 | 55.95768(11) | 200(5) ms | β− | 56V | 0+ | ||||||||||||
| 57Ti | 22 | 35 | 56.96307(22) | 95(8) ms | β− | 57V | 5/2−# | ||||||||||||
| 58Ti | 22 | 36 | 57.96681(20) | 55(6) ms | β− | 58V | 0+ | ||||||||||||
| 59Ti | 22 | 37 | 58.97222(32)# | 28.5(19) ms | β− | 59V | 5/2−# | ||||||||||||
| 59mTi | 108.5(5) keV | 615(11) ns | IT | 59Ti | 1/2−# | ||||||||||||||
| 60Ti | 22 | 38 | 59.97628(26) | 22.2(16) ms | β− | 60V | 0+ | ||||||||||||
| 61Ti | 22 | 39 | 60.98243(32)# | 15(4) ms | β− | 61V | 1/2−# | ||||||||||||
| 61m1Ti | 125.0(5) keV | 200(28) ns | IT | 61Ti | 5/2−# | ||||||||||||||
| 61m2Ti | 700.1(7) keV | 354(69) ns | IT | 61Ti | 9/2+# | ||||||||||||||
| 62Ti | 22 | 40 | 61.98690(43)# | 9# ms [>620 ns] |
0+ | ||||||||||||||
| 63Ti | 22 | 41 | 62.99371(54)# | 10# ms [>620 ns] |
1/2−# | ||||||||||||||
| 64Ti | 22 | 42 | 63.99841(64)# | 5# ms [>620 ns] |
0+ | ||||||||||||||
| This table header & footer: | |||||||||||||||||||
- ^ mTi – Excited nuclear isomer.
- ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- ^ a b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- ^
Modes of decay:
EC: Electron capture
n: Neutron emission p: Proton emission - ^ Bold symbol as daughter – Daughter product is stable.
- ^ ( ) spin value – Indicates spin with weak assignment arguments.
Titanium-44
editTitanium-44 (44Ti) is a radioactive isotope of titanium that undergoes electron capture to an excited state of scandium-44 with a half-life of 60 years, before the ground state of 44Sc and ultimately 44Ca are populated.[6] 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).[7]
Titanium-44 is produced in relative abundance in the alpha process in stellar nucleosynthesis and the early stages of supernova explosions.[8] It is produced when calcium-40 fuses with an alpha particle (helium-4 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 emissions from titanium-44 and its abundance.[7] It was observed in the Cassiopeia A supernova remnant and SN 1987A at a relatively high concentration, a consequence of delayed decay resulting from ionizing conditions.[6][7]
References
edit- ^ a b c d e Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
- ^ "Standard Atomic Weights: Titanium". CIAAW. 1993.
- ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
- ^ a b Barbalace, Kenneth L. (2006). "Periodic Table of Elements: Ti - Titanium". Retrieved 2006-12-26.
- ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
- ^ a b Motizuki, Y.; Kumagai, S. (2004). "Radioactivity of the key isotope 44Ti in SN 1987A". AIP Conference Proceedings. 704 (1): 369–374. arXiv:astro-ph/0312620. Bibcode:2004AIPC..704..369M. CiteSeerX 10.1.1.315.8412. doi:10.1063/1.1737130. S2CID 1700673.
- ^ a b c Mochizuki, Y.; Takahashi, K.; Janka, H.-Th.; Hillebrandt, W.; Diehl, R. (2008). "Titanium-44: Its effective decay rate in young supernova remnants, and its abundance in Cas A". Astronomy and Astrophysics. 346 (3): 831–842. arXiv:astro-ph/9904378.
- ^ Fryer, C.; Dimonte, G.; Ellinger, E.; Hungerford, A.; Kares, B.; Magkotsios, G.; Rockefeller, G.; Timmes, F.; Woodward, P.; Young, P. (2011). Nucleosynthesis in the Universe, Understanding 44Ti (PDF). ADTSC Science Highlights (Report). Los Alamos National Laboratory. pp. 42–43.
- Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", 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:
- de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
- Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
- "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
- Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.