Isotopes of titanium

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Isotopes of titanium  (22Ti)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
44Ti synth 59.1 y ε 44Sc
46Ti8.25% stable
47Ti7.44%stable
48Ti73.7%stable
49Ti5.41%stable
50Ti5.18%stable
Standard atomic weight Ar°(Ti)

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]

Contents

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


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 energyNormal proportion [1] Range of variation
39Ti221739.00268(22)#28.5(9) ms β+, p (93.7%)38Ca3/2+#
β+ (~6.3%)39Sc
β+, 2p (?%)37K
40Ti221839.990345(73)52.4(3) msβ+, p (95.8%)39Ca0+
β+ (4.2%)40Sc
41Ti221940.983148(30)81.9(5) msβ+, p (91.1%)40Ca3/2+
β+ (8.9%)41Sc
42Ti222041.97304937(29)208.3(4) msβ+42Sc0+
43Ti222142.9685284(61)509(5) msβ+43Sc7/2−
43m1Ti313.0(10) keV11.9(3) μs IT 43Ti(3/2+)
43m2Ti3066.4(10) keV556(6) nsIT43Ti(19/2−)
44Ti222243.95968994(75)59.1(3) y EC 44Sc0+
45Ti222344.95812076(90)184.8(5) minβ+45Sc7/2−
45mTi36.53(15) keV3.0(2) μsIT45Ti3/2−
46Ti222445.952626356(97)Stable0+0.0825(3)
47Ti222546.951757491(85)Stable5/2−0.0744(2)
48Ti222647.947940677(79)Stable0+0.7372(3)
49Ti222748.947864391(84)Stable7/2−0.0541(2)
50Ti222849.944785622(88)Stable0+0.0518(2)
51Ti222950.94660947(52)5.76(1) minβ51V3/2−
52Ti223051.9468835(29)1.7(1) minβ52V0+
53Ti223152.9496707(31)32.7(9) sβ53V(3/2)−
54Ti223253.950892(17)2.1(10) sβ54V0+
55Ti223354.955091(31)1.3(1) sβ55V(1/2)−
56Ti223455.95768(11)200(5) msβ56V0+
57Ti223556.96307(22)95(8) msβ57V5/2−#
58Ti223657.96681(20)55(6) msβ58V0+
59Ti223758.97222(32)#28.5(19) msβ59V5/2−#
59mTi108.5(5) keV615(11) nsIT59Ti1/2−#
60Ti223859.97628(26)22.2(16) msβ60V0+
61Ti223960.98243(32)#15(4) msβ61V1/2−#
61m1Ti125.0(5) keV200(28) nsIT61Ti5/2−#
61m2Ti700.1(7) keV354(69) nsIT61Ti9/2+#
62Ti224061.98690(43)#9# ms
[>620 ns]
0+
63Ti224162.99371(54)#10# ms
[>620 ns]
1/2−#
64Ti224263.99841(64)#5# ms
[>620 ns]
0+
This table header & footer:
  1. mTi  Excited nuclear isomer.
  2. ()  Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. #  Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. 1 2 #  Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. Modes of decay:
    EC: Electron capture
    n: Neutron emission
    p: Proton emission
  6. Bold symbol as daughter  Daughter product is stable.
  7. () spin value  Indicates spin with weak assignment arguments.

Titanium-44

Titanium-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

  1. 1 2 3 4 5 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.
  2. "Standard Atomic Weights: Titanium". CIAAW. 1993.
  3. 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.
  4. 1 2 Barbalace, Kenneth L. (2006). "Periodic Table of Elements: Ti - Titanium" . Retrieved 2006-12-26.
  5. 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.
  6. 1 2 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.
  7. 1 2 3 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 .
  8. 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.