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A term used to describe molecules and polyatomic ions that have one atom in center and four atoms at the corners of a tetrahedron.

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Physical Change

A change in which a substance changes from one physical state to another but no substances with different composition are formed. Example Gas to Liquid - Solid.

 

Leveling Effect

Effect by which all acids stronger than the acid that is characteristic of the solvent react with solvent to produce that acid, similar statement applies to bases. The strongest acid (base) that can exist in a given solvent is the acid (base) characteristic of the solvent.

Colligative Properties

Physical properties of solutions that depend upon the number but not the kind of solute particles present.

Ionic Compounds

Compounds containing predominantly ionic bonding.

Oxidation Numbers

Arbitrary numbers that can be used as mechanical aids in writing formulas and balancing equations, for single- atom ions they correspond to the charge on the ion, more electronegative atoms are assigned negative oxidation numbers (also called Oxidation states).

Kinetic-molecular Theory

A theory, that attempts to explain macroscopic observations on gases in microscopic observations on gases in microscopic observations on gases in microscopic or molecular terms.

Activity Series

A listing of metals (and hydrogen) in order of decreasing activity.

Valence Bond Theory

Assumes that covalent bonds are formed when atomic orbitals on different atoms overlap and the electrons are shared.

Acetic Acid

CA3COOH, clear, colorless liquid, pungent odor. Boiling point 140C, flash point 54C (closed cup), autoignition temperature 38OC.

Wild patina, is it so bad?

Usually this kind of patina appears on monuments. The most striking example is the Statue of Liberty in New York.