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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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London Forces

Very weak and very short-range attractive forces between short-lived temporary (induced) dipoles, also called dispersion Forces.

Tyndall Effect

The scattering of light by colloidal particles.

Ionization Isomers

Isomers that result from the interchange of ions inside and outside the coordination sphere.

Le Chatelier's Principle

States that a system at equilibrium, or striving to attain equilibrium, responds in such a way as to counteract any stress placed upon it.
If a stress (change of conditions) is applied to a system at equilibrium, the system shifts in the direction that reduces stress.

Curie (Ci)

The basic unit used to describe the intensity of radioactivity in a sample of material. One curie equals 37 billion disintegrations per second or approximately the amount of radioactivty given off by 1 gram of radium.

Atomic Number


Integral number of protons in the nucleus, defines the identity of element.
 

Activity of a component of ideal mixture

A dimensionless quantity whose magnitude is: equal to molar concentration in an ideal solution, equal to partial pressure in an ideal gas mixture, and defined as 1 for pure solids or liquids.

Heat Capacity

The amount of heat required to raise the temperature of a body (of any mass) one degree Celsius.

Valence Shell Electron Pair Repulsion Theory

Assumes that electron pairs are arranged around the central element of a molecule or polyatomic ion so that there is maximum separation (and minimum repulsion) among regions of high electron density.

 

Metathesis Reactions

Reactions in which two compounds react to form two new compounds, with no changes in oxidation number. Reactions in which the ions of two compounds exchange partners.