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Energy required to pair two electrons in the same orbital.

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Total Ionic Equation

Equation for a chemical reaction written to show the predominant form of all species in aqueous solution or in contact with water.

Single Bond

Covalent bond resulting from the sharing of two electrons (one pair) between two atoms.

Salinometer

An instrument for measuring the amount of salt in a solution. Also,"salimeter, salometer."

Critical Point

The combination of critical temperature and critical pressure of a substance.

Alkynes

Unsaturated hydrocarbons that contain one or more carbon-carbon triple bonds.

Calorimeter

A device used to measure the heat transfer between system and surroundings.

Binding Energy (nuclear binding energy)

The energy equivalent (E = mc^2) of the mass deficiency of an atom.  where: E = is the energy in joules, m is the mass in kilograms, and c is the speed of light in m/s^2

Aryl Group

Group of atoms remaining after a hydrogen atom is removed from the aromatic system.

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.

Bronsted-Lowry Acid

A proton donor.