92 | The History and Use of Our Earth’s Chemical Elements Common฀Uses

92 | The History and Use of Our Earth’s Chemical Elements Common฀Uses

Given titanium’s lightness, strength, and resistance to corrosion and high temperatures, its most common use is in alloys with other metals for constructing aircraft, jet engines, and mis- siles. Its alloys also make excellent armor plates for tanks and warships. It is the major metal used for constructing the stealth aircraft that are difficult to detect by radar.

Titanium’s noncorrosive and lightweight properties make it useful in the manufacture of laboratory and medical equipment that will withstand acid and halogen salt corrosion. These same properties make it an excellent metal for surgical pins and screws in the repair of broken bones and joints.

It has many other uses as an abrasive, as an ingredient of cements, and as a paint pigment in the oxide form and in the paper and ink industries, in batteries for space vehicles, and wherever a metal is needed to resist chlorine (seawater) corrosion.

Examples฀of฀Compounds Titanium’s ions, in the three different oxidation states, react with chlorine as follows:

Titanium chloride (II): Ti 2+ + 2Cl - → TiCl 2 (titanium dichloride) Titanium chloride (III): Ti 3+ + 3Cl - → TiCl 3 (titanium trichloride)

Titanium chloride (IV): Ti 4+ + 4Cl - → TiCl 3 (titanium tetrachloride)

The same sequence using the three oxidations states of titanium occurs with oxygen to form

II, III, and IV titanium oxides. Titanium (IV) dioxide (TiO 2 ), also known as rutile, is one of the best-known compounds used as a paint pigment. It is ideal for paints exposed to severe temperatures and marine climates because of its inertness and self-cleaning attributes. It is also used in manufacture of glassware, ceramics, enamels, welding rods, and floor coverings.

Titanium (IV) tetrachloride (TiCl 4 ) produces a dense white smoke-like vapor when exposed to moist air. It is used as smoke screens and for skywriting, as well in theatrical productions where fog or smoke is required for the scene.

Titanium (IV) carbide (TiC) is used as an additive to carbide to make high-temperature cutting tools, cements, abrasives, and coatings.

Titanium (IV) nitride (TiN) is a hard brittle metal that is used in alloys, to manufacture semiconducting instruments, as cements, and as an abrasive. Titanium (II) bromide (TiB 2 ) is used for metallurgy, high-temperature electrical wiring, electronics, computers, high temperature-resistant coatings, and super alloys, including strong lightweight aluminum alloys.

Hazards Almost all of titanium’s compounds, as well as the pure metal when in powder form, are

extremely flammable and explosive. Titanium metal will ignite in air at 1200°C and will burn in an atmosphere of nitrogen. Titanium fires cannot be extinguished by using water or carbon dioxide extinguishers. Sand, dirt, or special foams must be used to extinguish burning titanium.

Guide to the Elements | 93 VANADIUM

SYMBOL:฀V฀ PERIOD:฀4฀ GROUP:฀5฀(VB)฀ ATOMIC฀NO:฀23 ATOMIC฀MASS:฀50.9415฀amu฀ VALENCE:฀2,฀3,฀4,฀and฀5฀ OXIDATION฀STATE:฀+2,฀+3,฀+4,฀

and฀+5฀ NATURAL฀STATE:฀Solid ORIGIN฀OF฀NAME:฀Named฀after฀the฀Scandinavian฀mythological฀goddess฀Vanadis฀because฀

of฀the฀many฀colors฀exhibited฀by฀vanadium’s฀compounds. ISOTOPES:฀There฀are฀27฀isotopes฀of฀vanadium.฀Only฀vanadium-51฀is฀stable฀and฀makes฀up฀ 99.75%฀of฀the฀total฀vanadium฀on฀Earth.฀The฀other฀0.25%฀of฀the฀vanadium฀found฀on฀ Earth฀is฀from฀the฀radioisotope฀vanadium-50,฀which฀has฀such฀a฀long฀half-life฀of฀1.4×10 +17 ฀

years฀that฀it฀is฀considered฀stable.฀The฀other฀radioactive฀isotopes฀have฀half-lives฀ranging฀ from฀150฀nanoseconds฀to฀one฀year.

ELECTRON฀CONFIGURATION ฀ Energy฀Levels/Shells/Electrons฀ Orbitals/Electrons

s2,฀p6

฀ 3-M฀=฀11฀

s2,฀p6,฀d3

฀ 4-N฀=฀2฀

s2

Properties Vanadium is a silvery whitish-gray metal that is somewhat heavier than aluminum, but

lighter than iron. It is ductile and can be worked into various shapes. It is like other transition metals in the way that some electrons from the next-to-outermost shell can bond with other elements. Vanadium forms many complicated compounds as a result of variable valences. This attribute is responsible for the four oxidation states of its ions that enable it to combine with most nonmetals and to at times even act as a nonmetal. Vanadium’s melting point is 1890°C,

its boiling point is 3380°C, and its density is 6.11 g/cm 3 .