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)
  • 47.867±0.001
  • 47.867±0.001 (abridged) [2] [3]

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)
[n 2] [n 3]
Half-life
[n 4]
Decay
mode

[n 5]
Daughter
isotope

[n 6]
Spin and
parity
[n 7] [n 4]
Natural abundance (mole fraction)
Excitation energyNormal proportionRange of variation
39Ti221739.00161(22)#31(4) ms
[31(+6-4) ms]
β+, p (85%)38Ca3/2+#
β+ (15%)39Sc
β+, 2p (<.1%)37K
40Ti221839.99050(17)53.3(15) msβ+ (56.99%)40Sc0+
β+, p (43.01%)39Ca
41Ti221940.98315(11)#80.4(9) msβ+, p (>99.9%)40Ca3/2+
β+ (<.1%)41Sc
42Ti222041.973031(6)199(6) msβ+42Sc0+
43Ti222142.968522(7)509(5) msβ+43Sc7/2−
43m1Ti313.0(10) keV12.6(6) μs(3/2+)
43m2Ti3066.4(10) keV560(6) ns(19/2−)
44Ti222243.9596901(8)60.0(11) y EC 44Sc0+
45Ti222344.9581256(11)184.8(5) minβ+45Sc7/2−
46Ti222445.9526316(9)Stable0+0.0825(3)
47Ti222546.9517631(9)Stable5/2−0.0744(2)
48Ti222647.9479463(9)Stable0+0.7372(3)
49Ti222748.9478700(9)Stable7/2−0.0541(2)
50Ti222849.9447912(9)Stable0+0.0518(2)
51Ti222950.946615(1)5.76(1) minβ51V3/2−
52Ti223051.946897(8)1.7(1) minβ52V0+
53Ti223152.94973(11)32.7(9) sβ53V(3/2)−
54Ti223253.95105(13)1.5(4) sβ54V0+
55Ti223354.95527(16)490(90) msβ55V3/2−#
56Ti223455.95820(21)164(24) msβ (>99.9%)56V0+
β, n (<.1%)55V
57Ti223556.96399(49)60(16) msβ (>99.9%)57V5/2−#
β, n (<.1%)56V
58Ti223657.96697(75)#54(7) msβ58V0+
59Ti223758.97293(75)#30(3) msβ59V(5/2−)#
60Ti223859.97676(86)#22(2) msβ60V0+
61Ti223960.98320(97)#10# ms
[>300 ns]
β61V1/2−#
β, n60V
62Ti224061.98749(97)#10# ms0+
63Ti224162.99442(107)#3# ms1/2−#
64Ti [5] 224263.998410(640)#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]

Related Research Articles

Francium (87Fr) has no stable isotopes. A standard atomic weight cannot be given. Its most stable isotope is 223Fr with a half-life of 22 minutes, occurring in trace quantities in nature as an intermediate decay product of 235U.

Bismuth (83Bi) has 41 known isotopes, ranging from 184Bi to 224Bi. Bismuth has no stable isotopes, but does have one very long-lived isotope; thus, the standard atomic weight can be given as 208.98040(1). Although bismuth-209 is now known to be radioactive, it has classically been considered to be a stable isotope because it has a half-life of approximately 2.01×1019 years, which is more than a billion times the age of the universe. Besides 209Bi, the most stable bismuth radioisotopes are 210mBi with a half-life of 3.04 million years, 208Bi with a half-life of 368,000 years and 207Bi, with a half-life of 32.9 years, none of which occurs in nature. All other isotopes have half-lives under 1 year, most under a day. Of naturally occurring radioisotopes, the most stable is radiogenic 210Bi with a half-life of 5.012 days. 210mBi is unusual for being a nuclear isomer with a half-life multiple orders of magnitude longer than that of the ground state.

<span class="mw-page-title-main">Isotopes of thallium</span> Nuclides with atomic number of 81 but with different mass numbers

Thallium (81Tl) has 41 isotopes with atomic masses that range from 176 to 216. 203Tl and 205Tl are the only stable isotopes and 204Tl is the most stable radioisotope with a half-life of 3.78 years. 207Tl, with a half-life of 4.77 minutes, has the longest half-life of naturally occurring Tl radioisotopes. All isotopes of thallium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

Naturally occurring tungsten (74W) consists of five isotopes. Four are considered stable (182W, 183W, 184W, and 186W) and one is slightly radioactive, 180W, with an extremely long half-life of 1.8 ± 0.2 exayears (1018 years). On average, two alpha decays of 180W occur per gram of natural tungsten per year, so for most practical purposes, 180W can be considered stable. Theoretically, all five can decay into isotopes of element 72 (hafnium) by alpha emission, but only 180W has been observed to do so. The other naturally occurring isotopes have not been observed to decay (they are observationally stable), and lower bounds for their half-lives have been established:

Natural hafnium (72Hf) consists of five observationally stable isotopes (176Hf, 177Hf, 178Hf, 179Hf, and 180Hf) and one very long-lived radioisotope, 174Hf, with a half-life of 7.0×1016 years. In addition, there are 34 known synthetic radioisotopes, the most stable of which is 182Hf with a half-life of 8.9×106 years. This extinct radionuclide is used in hafnium–tungsten dating to study the chronology of planetary differentiation.

Naturally occurring ytterbium (70Yb) is composed of seven stable isotopes: 168Yb, 170Yb–174Yb, and 176Yb, with 174Yb being the most abundant. Twenty-seven radioisotopes have been characterized, with the most stable being 169Yb with a half-life of 32.026 days, 175Yb with a half-life of 4.185 days, and 166Yb with a half-life of 56.7 hours. All of the remaining radioactive isotopes have half-lives that are less than 2 hours, and the majority of these have half-lives that are less than 20 minutes. This element also has 12 meta states, with the most stable being 169mYb.

Naturally occurring thulium (69Tm) is composed of one stable isotope, 169Tm. Thirty-six radioisotopes have been characterized, with the most stable being 171Tm with a half-life of 1.92 years, 170Tm with a half-life of 128.6 days, 168Tm with a half-life of 93.1 days, and 167Tm with a half-life of 9.25 days. All of the remaining radioactive isotopes have half-lives that are less than 64 hours, and the majority of these have half-lives that are less than 2 minutes. This element also has 26 meta states, with the most stable being 164mTm, 160mTm and 155mTm.

Naturally occurring terbium (65Tb) is composed of one stable isotope, 159Tb. Thirty-seven radioisotopes have been characterized, with the most stable being 158Tb with a half-life of 180 years, 157Tb with a half-life of 71 years, and 160Tb with a half-life of 72.3 days. All of the remaining radioactive isotopes have half-lives that are less than 6.907 days, and the majority of these have half-lives that are less than 24 seconds. This element also has 27 meta states, with the most stable being 156m1Tb, 154m2Tb and 154m1Tb.

Naturally occurring cerium (58Ce) is composed of 4 stable isotopes: 136Ce, 138Ce, 140Ce, and 142Ce, with 140Ce being the most abundant and the only one theoretically stable; 136Ce, 138Ce, and 142Ce are predicted to undergo double beta decay but this process has never been observed. There are 35 radioisotopes that have been characterized, with the most stable being 144Ce, with a half-life of 284.893 days; 139Ce, with a half-life of 137.640 days and 141Ce, with a half-life of 32.501 days. All of the remaining radioactive isotopes have half-lives that are less than 4 days and the majority of these have half-lives that are less than 10 minutes. This element also has 10 meta states.

<span class="mw-page-title-main">Isotopes of lanthanum</span> Nuclides with atomic number of 57 but with different mass numbers

Naturally occurring lanthanum (57La) is composed of one stable (139La) and one radioactive (138La) isotope, with the stable isotope, 139La, being the most abundant (99.91% natural abundance). There are 39 radioisotopes that have been characterized, with the most stable being 138La, with a half-life of 1.02×1011 years; 137La, with a half-life of 60,000 years and 140La, with a half-life of 1.6781 days. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these have half-lives that are less than 1 minute. This element also has 12 nuclear isomers, the longest-lived of which is 132mLa, with a half-life of 24.3 minutes.

There are 39 known isotopes and 17 nuclear isomers of tellurium (52Te), with atomic masses that range from 104 to 142. These are listed in the table below.

Indium (49In) consists of two primordial nuclides, with the most common (~ 95.7%) nuclide (115In) being measurably though weakly radioactive. Its spin-forbidden decay has a half-life of 4.41×1014 years, much longer than the currently accepted age of the Universe.

Naturally occurring ruthenium (44Ru) is composed of seven stable isotopes. Additionally, 27 radioactive isotopes have been discovered. Of these radioisotopes, the most stable are 106Ru, with a half-life of 373.59 days; 103Ru, with a half-life of 39.26 days and 97Ru, with a half-life of 2.9 days.

Natural yttrium (39Y) is composed of a single isotope yttrium-89. The most stable radioisotopes are 88Y, which has a half-life of 106.6 days and 91Y with a half-life of 58.51 days. All the other isotopes have half-lives of less than a day, except 87Y, which has a half-life of 79.8 hours, and 90Y, with 64 hours. The dominant decay mode below the stable 89Y is electron capture and the dominant mode after it is beta emission. Thirty-five unstable isotopes have been characterized.

Arsenic (33As) has 33 known isotopes and at least 10 isomers. Only one of these isotopes, 75As, is stable; as such, it is considered a monoisotopic element. The longest-lived radioisotope is 73As with a half-life of 80 days. Arsenic has been proposed as a "salting" material for nuclear weapons. A jacket of 75As, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope 76As with a half-life of 1.0778 days and produce approximately 1.13 MeV gamma radiation, significantly increasing the radioactivity of the weapon's fallout for several hours. Such a weapon is not known to have ever been built, tested, or used.

Germanium (32Ge) has five naturally occurring isotopes, 70Ge, 72Ge, 73Ge, 74Ge, and 76Ge. Of these, 76Ge is very slightly radioactive, decaying by double beta decay with a half-life of 1.78 × 1021 years (130 billion times the age of the universe).

Copper (29Cu) has two stable isotopes, 63Cu and 65Cu, along with 27 radioisotopes. The most stable radioisotope is 67Cu with a half-life of 61.83 hours, while the least stable is 54Cu with a half-life of approximately 75 ns. Most have half-lives under a minute. Unstable copper isotopes with atomic masses below 63 tend to undergo β+ decay, while isotopes with atomic masses above 65 tend to undergo β decay. 64Cu decays by both β+ and β.

Naturally occurring chromium (24Cr) is composed of four stable isotopes; 50Cr, 52Cr, 53Cr, and 54Cr with 52Cr being the most abundant (83.789% natural abundance). 50Cr is suspected of decaying by β+β+ to 50Ti with a half-life of (more than) 1.8×1017 years. Twenty-two radioisotopes, all of which are entirely synthetic, have been characterized, the most stable being 51Cr with a half-life of 27.7 days. All of the remaining radioactive isotopes have half-lives that are less than 24 hours and the majority of these have half-lives that are less than 1 minute. This element also has two meta states, 45mCr, the more stable one, and 59mCr, the least stable isotope or isomer.

Naturally occurring scandium (21Sc) is composed of one stable isotope, 45Sc. Twenty-five 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 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 states with the most stable being 44m2Sc.

Berkelium (97Bk) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 243Bk in 1949. There are 20 known radioisotopes, from 230Bk and 233Bk to 253Bk, and 6 nuclear isomers. The longest-lived isotope is 247Bk with a half-life of 1,380 years.

References

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