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Absorption of high energy radiation by a substance and subsequent emission of visible light.

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Bronsted-Lowry Base

A proton acceptor

Rate-law Expression

Equation relating the rate of a reaction to the concentrations of the reactants and the specific rate of the constant.

yttrium

A rare trivalent metallic element, found in gadolinite and other minerals. Symbol: Y, at. wt.: 88.905, at. no.: 39, sp. gr.: 4.47. Cf."rare-earth element."

Yttrium has a silver-metallic luster and is relatively stable in air unless finely divided. Turnings of the metal, however, ignite in air if their temperature exceeds 400oC. Yttrium oxide is one of the most important compounds of yttrium and accounts for the largest use. It is widely used in making YVO4 europium, and Y2O3 europium phosphors to give the red color in color television tubes.

Electronic Transition

The transfer of an electron from one energy level to another.

Acid Anhydride

Compound produced by dehydration of a carbonic acid. General formula is R--C--O--C--R. Chemical compound that reacts with water to form an acid and are usually oxides of nonmetallic elements.

Ionic Geometry

The arrangement of atoms (not lone pairs of electrons) about the central atom of a polyatomic ion.

Ampere

Unit of electrical current, one ampere equals one coulomb per second.

 

Condensation

Liquefaction of vapor.

Secondary Voltaic Cells

Voltaic cells that can be recharged, original reactanats can be regenerated be reversing the direction of the current flow.

Supersaturated Solution

A solution that contains a higher than saturation concentration of solute, slight disturbance or seeding causes crystallization of excess solute.