Titanium

Scandium - Titanium - Vanadium Ti Zr       Full table
General
Name, Symbol, Number	Titanium, Ti, 22
Chemical series	Transition metals
Group, Period, Block	4[?], 4 , d
Density, Hardness	4507 kg/m3, 6
Appearance	Silvery metallic
Atomic Properties
Atomic weight	47.867 amu
Atomic radius (calc.)	140 (176) pm
Covalent radius	136 pm
van der Waals radius	no data
Electron configuration	[Ar]3d2 4s2
e- 's per energy level	2, 8, 10, 2
Oxidation state (Oxide)	4 (amphoteric)
Crystal structure	Hexagonal
Physical Properties
State of matter	Solid (__)
Melting point	1941 K (3034 °F)
Boiling point	3560 K (5949 °F)
Molar volume	10.64 ×10-3 m3/mol
Heat of vaporization	421 kJ/mol
Heat of fusion	15.45 kJ/mol
Vapor pressure	0.49 Pa at 1933 K
Velocity of sound	4140 m/s at 293.15 K
Miscellaneous
Electronegativity	1.54 (Pauling scale)
Specific heat capacity	520 J/(kg*K)
Electrical conductivity	2.34 106/m ohm
Thermal conductivity	21.9 W/(m*K)
1st ionization potential	658.8 kJ/mol
2nd ionization potential	1309.8 kJ/mol
3rd ionization potential	2652.5 kJ/mol
4th ionization potential	4174.6 kJ/mol
5th ionization potential	9581 kJ/mol
6th ionization potential	11533 kJ/mol
7th ionization potential	13590 kJ/mol
8th ionization potential	16440 kJ/mol
9th ionization potential	18530 kJ/mol
10th ionization potential	20833 kJ/mol
Most Stable Isotopes
iso NA half-life DM DE MeV DP 44Ti {syn.} 63 y ε 0.268 44Sc 46Ti 8.0% Ti is stable with 24 neutrons 47Ti 7.3% Ti is stable with 25 neutrons 48Ti 73.8% Ti is stable with 26 neutrons 49Ti 5.5% Ti is stable with 27 neutrons 50Ti 5.4% Ti is stable with 28 neutrons
SI units & STP are used except where noted.

Titanium is a chemical element in the periodic table that has the symbol Ti and atomic number 22. A light, strong, white-metallic, lustrous, corrosion-resistant transition metal, titanium is used in strong light-weight alloys and in white pigments. This element occurs in numerous minerals with the main sources being rutile and ilmenite.

Table of contents 1 Notable Characteristics 2 Applications 3 History 4 Occurrence 4.1 Production 5 Compounds 6 Isotopes 7 Precautions 8 External Links

Notable Characteristics Titanium is a metallic element which is well known for its excellent corrosion resistance (almost as resistant as platinum) and for its high strength-to-weight ratio. It is light, strong, easily fabricated metal with low density that, when pure, is lustrous, and metallic-white. The relatively high melting point of this element makes it useful as a refractory metal[?]. Titanium is as strong as steel, but 45% lighter and 60% heavier than aluminium, but twice as strong.

This metal forms a passive oxide coating when exposed to air but when it is in an oxygen-free environment it is ductile. The metal, which burns when heated in air, is also the only element that can burn in pure nitrogen gas. Titanium is resistant to dilute sulfuric and hydrochloric acid, along with chlorine gas, chloride solutions, and most organic acids .

Experiments have shown that natural titanium becomes very radioactive after it is bombardment with deuterons emitting mainly positrons and hard gamma rays. The metal is dimorphic with the hexagonal alpha form changing into the cubic beta form very slowly at around 880° C. When it is red hot the metal combines with oxygen and when it reaches 550°C it combines with chlorine. Applications Approximately 95% of titanium is consumed in the form of titanium dioxide (TiO₂), a white permanent pigment with good covering power in paints, paper, and plastics. Paints made with titanium dioxide are excellent reflectors of infrared radiation and are therefore used extensively by astronomers.

Because of its strength, light weight and ability to withstand extreme temperatures, titanium alloys are principally used in aircraft and missiles, although applications in consumer products such as golf clubs[?], mountain bikes, and laptop computers[?] are becoming more common. Titanium is often alloyed with aluminum, iron, manganese, molybdenum and with other metals. Other uses;

• Due to excellent resistance to sea water, it is used to make propeller shafts and rigging.
• It is used to produce relatively soft artificial gemstones.
• Titanium tetrachloride[?] is used to iridize glass and because it fumes strongly in air it is also used to make smoke screens[?].
• Because it is considered to be physiologically inert, the metal is used in joint replacement implants such as hip ball and sockets.
• Because of both its inertness and its ability to be attractively colored, titanium is a popular metal for use in Body piercing.

A potential use of titanium is in desalination plants. History Titanium (Latin Titans, the first sons of Gaia) was discovered in England by Reverend William Gregor[?] in 1791 who recognized the presence of a new element in ilmenite. The element was rediscovered several years later by German chemist Heinrich Klaproth[?] in rutile ore. In 1795 Klaproth named the new element after the Titans of Greek mythology.

Pure metallic titanium (99.9%) was first prepared in 1910 by Matthew A. Hunter[?] by heating TiCl₄ with sodium in a steel bomb at 700-800°C.

Titanium metal wasn't used outside the laboratory until 1946 when William Justin Kroll[?] proved that titanium could be commercially produced by reducing titanium tetrachloride[?] with magnesium (which is the method still used today). Occurrence Titanium metal is not found unbound to other elements in nature but the element is the ninth most abundant element in the earth's crust and is present in most igneous rocks and in sediments derived from them. Titanium occurs primarily in the minerals anatase, brookite, ilmenite, leucoxene, perovskite, rutile, and sphene and is found in titanates and in many iron ores. Of these minerals, only ilmenite, leucoxene, and rutile have significant economic importance. Significant titanium ore deposits are in Australia, Scandinavia, North America and Malaysia.

This metal is found in meteorites and has been detected in the sun and in M-type stars. Rocks brought back from the moon during the Apollo 17 mission are composed of 12.1% TiO₂. Titanium is also found in coal ash, plants, and even the human body.

Production

Titanium metal is produced commercially by reducing TiCl₄ with magnesium, a process developed in 1946 by William Justin Kroll[?]. This is a complex and expensive batch process, but a newer process called the "FFC-Cambridge" method may displace this older process. This method uses the feedstock titanium dioxide powder (which is a refined form of rutile) to make the end product which is a continuous stream of molten titanium suitable for immediate use in the manufacture of commercial alloys.

It is hoped that the FFC-Cambridge method will render titanium a less rare and expensive material for the aerospace industry and the luxury goods market, and will be seen in many products currently manufactured using aluminum and specialist grades of steel. Compounds Although titanium metal is relatively uncommon, due to the cost of extraction, titanium dioxide is cheap, readily available in bulk, and very widely used as a white pigment in paint, plastic and construction cement. TiO₂ powder is chemically inert, resists fading in sunlight, and is very opaque: this allows it to impart a pure and brilliant white color to the brown or gray chemicals that form the majority of household plastics. Pure titanium dioxide has a very high index of refraction and an optical dispersion higher than diamond. Star sapphires[?] and rubies get their asterism from the titanium dioxide present in them. Isotopes Naturally occurring titanium is composed of 5 stable isotopes; Ti-46, Ti-47, Ti-48, Ti-49 and Ti-50 with Ti-48 being the most abundant (73.8% natural abundance). 11 radioisotopes have been characterized with the most stable being Ti-44 with a half-life of 63 years, Ti-45 with a half-life of 184.8 minutes, Ti-51 with a half-life of 5.76 minutes, and Ti-52 with a half-life of 1.7 minutes. All of the remaining radioactive isotopes have half-lifes that are less than 33 seconds and the majority of these have half lifes that are less than half a second.

The isotopes of titanium range in atomic weight from 39.99 amu (Ti-40) to 57.966 amu (Ti-58). The primary decay mode before the most abundant stable isotope, Ti-48, is electron capture and the primary mode after is beta emission. The primary decay products before Ti-48 are element 21 (scandium) isotopes and the primary products after are element 23 (vanadium) isotopes. Precautions When in a powered form, titanium metal poses a significant fire hazard but salts of titanium are often considered to be relatively harmless. Chlorine compounds such as TiCl₃ and TiCl₄ should be considered to be corrosive, however. Titanium also has a tendency to bio-accumulate in tissues that contain silica but it does not play any known biological role in humans.

External Links

• WebElements.com - Titanium (http://www.webelements.com/webelements/elements/text/Ti/index)
• EnvironmentalChemistry.com - Titanium (http://environmentalchemistry.com/yogi/periodic/Ti)