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Refers to species that have only six electrons in the highest energy level of the central element (many Lewis acids).

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Magnetic Quantum Number (mc)

Quantum mechanical solution to a wave equation that designates the particular orbital within a given set (s, p, d, f ) in which a electron resides.

Zone Refining

A method of purifying a bar of metal by passing it through an induction heater, this causes impurties to move along a melted portion. This method applies the fact when a metal crystallizes on cooling, impurities are automatically expelled as they do not form part of the crystal.

Mass Action Expression

For a reversible reaction, aA + bB cC + dD the product of the concentrations of the products (species on the right), each raised to the power that corresponds to its coefficient in the balanced chemical equation, divided by the product of the concentrations of reactants (species on the left), each raised to the power that corresponds to its coefficient in the balanced chemical equation. At equilibrium the mass action expression is equal to K, at other times it is Q.[C]c[D]d [A]a[B]b = Q, or at equilibrium K.


The ability of a substance to become permanently magnetized by exposure to an external magnetic field.

Nonbonding Orbital

A molecular orbital derived only from an atomic orbital of one atom, lends neither stability nor instability to a molecule or ion when populated with electrons.

Substitution Reaction

A reaction in which an atom or a group of atoms is replaced by another atom or group of atoms.

Heat Capacity

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

What are Compound Microscopes?

Most of the microscopes used today are compound. A compound microscope features two or more lenses. A hollow cylinder called the tube connects the two lenses.

The top lens, the one people look through, is called the eyepiece. The bottom lens is known as the objective lens. Below the two lenses is the stage, with the illuminator below that.

Handmade crystal glass as a work of art

In order for the colored crystal to open in all its beauty and sparkle with every face natural light is required. Handmade crystal glass has specific tactile and aesthetic properties - it is pleasant to touch, it seems to radiate heat. To appreciate the quality and beauty of such things, of course, it is not enough to look at the picture.

Inner Orbital Complex

Valence bond designation for a complex in which the metal ion utilizes d orbitals for one shell inside the outermost occupied shell in its hybridization.