Titanium

For other uses, see Titanium (disambiguation).

Titanium, 22Ti
Titanium
Pronunciation
Appearancesilvery grey-white metallic
Standard atomic weight Ar°(Ti)
Titanium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
–
↑
Ti
↓
Zr
scandium ← titanium → vanadium
Atomic number (Z)22
Groupgroup 4
Periodperiod 4
Block  d-block
Electron configuration[Ar] 3d2 4s2
Electrons per shell2, 8, 10, 2
Physical properties
Phase at STPsolid
Melting point1941 K ​(1668 °C, ​3034 °F)
Boiling point3560 K ​(3287 °C, ​5949 °F)
Density (at 20° C)4.502 g/cm3 [4]
when liquid (at m.p.)4.11 g/cm3
Heat of fusion14.15 kJ/mol
Heat of vaporization425 kJ/mol
Molar heat capacity25.060 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1982 2171 (2403) 2692 3064 3558
Atomic properties
Oxidation statescommon: +4
−2[5], −1,[6] 0,[7] +1,[8] +2,[6] +3[6]
ElectronegativityPauling scale: 1.54
Ionization energies
  • 1st: 658.8 kJ/mol
  • 2nd: 1309.8 kJ/mol
  • 3rd: 2652.5 kJ/mol
  • (more)
Atomic radiusempirical: 147 pm
Covalent radius160±8 pm
Color lines in a spectral range
Spectral lines of titanium
Other properties
Natural occurrenceprimordial
Crystal structure ​hexagonal close-packed (hcp) (hP2)
Lattice constants
Hexagonal close packed crystal structure for titanium
a = 295.05 pm
c = 468.33 pm (at 20 °C)[4]
Thermal expansion9.68×10−6/K (at 20 °C)[a]
Thermal conductivity21.9 W/(m⋅K)
Electrical resistivity420 nΩ⋅m (at 20 °C)
Magnetic orderingparamagnetic
Molar magnetic susceptibility+153.0×10−6 cm3/mol (293 K)[9]
Young's modulus116 GPa
Shear modulus44 GPa
Bulk modulus110 GPa
Speed of sound thin rod5090 m/s (at r.t.)
Poisson ratio0.32
Mohs hardness6.0
Vickers hardness830–3420 MPa
Brinell hardness716–2770 MPa
CAS Number7440-32-6
History
DiscoveryWilliam Gregor (1791)
First isolationJöns Jakob Berzelius (1825)
Named byMartin Heinrich Klaproth (1795)
Isotopes of titanium
Main isotopes[10] Decay
abun­dance half-life (t1/2) mode pro­duct
44Ti synth 59.1 y ε 44Sc
46Ti 8.25% stable
47Ti 7.44% stable
48Ti 73.7% stable
49Ti 5.41% stable
50Ti 5.18% stable
 Category: Titanium
| references

Titanium is a chemical element; it has 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 sea water, aqua regia, and chlorine.

Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and was named by Martin Heinrich Klaproth after the Titans of Greek mythology. The element occurs within a number of minerals, principally rutile and ilmenite, which are widely distributed in the Earth's crust and lithosphere; it is found in almost all living things, as well as bodies of water, rocks, and soils.[11] The metal is extracted from its principal mineral ores by the Kroll and Hunter processes.[12] The most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments.[13] Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and catalysts; and titanium trichloride (TiCl3), which is used as a catalyst in the production of polypropylene.[11]

Titanium can be alloyed with iron, aluminium, vanadium, and molybdenum, among other elements. The resulting titanium alloys are strong, lightweight, and versatile, with applications including aerospace (jet engines, missiles, and spacecraft), military, industrial processes (chemicals and petrochemicals, desalination plants, pulp, and paper), automotive, agriculture (farming), sporting goods, jewelry, and consumer electronics.[11] Titanium is also considered one of the most biocompatible metals, leading to a range of medical applications including prostheses, orthopedic implants, dental implants, and surgical instruments.[14]

The two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element.[15] In its unalloyed condition, titanium is as strong as some steels, but less dense.[16] There are two allotropic forms[17] and five naturally occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant (73.8%).[18]

  1. ^ "titanium". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 20 December 2019.
  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. (4 May 2022). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ^ a b Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
  5. ^ Ti(-2) is known in Ti(CO)2−6; see John E. Ellis (2006). "Adventures with Substances Containing Metals in Negative Oxidation States". Inorganic Chemistry. 45 (8). doi:10.1021/ic052110i.
  6. ^ a b c Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. ISBN 978-0-08-037941-8.
  7. ^ Jilek, Robert E.; Tripepi, Giovanna; Urnezius, Eugenijus; Brennessel, William W.; Young, Victor G. Jr.; Ellis, John E. (2007). "Zerovalent titanium–sulfur complexes. Novel dithiocarbamato derivatives of Ti(CO)6:[Ti(CO)4(S2CNR2)]−". Chem. Commun. (25): 2639–2641. doi:10.1039/B700808B. PMID 17579764.
  8. ^ Andersson, N.; et al. (2003). "Emission spectra of TiH and TiD near 938 nm". J. Chem. Phys. 118 (8): 10543. Bibcode:2003JChPh.118.3543A. doi:10.1063/1.1539848.
  9. ^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  10. ^ 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.
  11. ^ a b c Cite error: The named reference EBC was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference LANL was invoked but never defined (see the help page).
  13. ^ Krebs, Robert E. (2006). The History and Use of Our Earth's Chemical Elements: A Reference Guide (2nd ed.). Westport, CT: Greenwood Press. ISBN 978-0-313-33438-2.
  14. ^ Medical, Tokyo; University, Dental (24 May 2022). "Exploring what gives titanium implants their remarkable biocompatibility". Phys.org. Retrieved 2 May 2024.
  15. ^ Donachie 1988, p. 11
  16. ^ Barksdale 1968, p. 738
  17. ^ Cite error: The named reference TICE6th was invoked but never defined (see the help page).
  18. ^ Barbalace, Kenneth L. (2006). "Periodic Table of Elements: Ti – Titanium". Retrieved 26 December 2006.


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