Matter & Energy


Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances.

Vanadium

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Vanadium, symbol V, silver-white metallic element with an atomic number of 23. Vanadium is one of the transition elements of the periodic table. It was discovered in 1801 in Mexico by Andrés Manuel del Rio, but it was mistaken for a form of chromium. Vanadium was rediscovered in about 1830 by the Swedish chemist Nils Gabriel Sefström.

PROPERTIES AND OCCURRENCE

Vanadium takes a high polish and is one of the hardest of all metals. It melts at about 1890° C (about 3434° F), boils at about 3380° C (about 6116° F), and has a specific gravity of 5.96. The atomic weight of vanadium is 50.941. Vanadium is soluble in nitric and sulfuric acids and insoluble in hydrochloric acid, dilute sodium hydroxide, and dilute alcohol. Vanadium forms several acidic oxides, the most important of which are the dark green trioxide and the orange pentoxide. Other important compounds include vanadium monosulfide, vanadium trisulfide, vanadium dichloride, vanadium trichloride, vanadium dihydroxide, and metavanadic acid.

Vanadium ranks about 19th in abundance of the elements in the earth's crust. It is never found in the pure state, but occurs in combination with various minerals throughout the world.

USES

Because of its hardness and great tensile strength, the metal is used in many alloys such as ferrovanadium, nickel vanadium, and chrome vanadium. Chrome-vanadium steels are used in the production of springs and in transmission gears and other engine parts. Titanium-vanadium alloys are used for missile cases, jet-engine housings, and nuclear-reactor components. As a catalyst, vanadium has largely replaced platinum in the manufacture of sulfuric acid and is employed widely as a photographic developer, as a reducing agent, and as a drying agent in various paints.