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The nuclear charge experienced by the outermost electrons of an atom, the actual nuclear charge minus the effects of shielding due to inner-shell electrons.
Example: Set of dx2-y2 and dz2 orbitals, those d orbitals within a set with lobes directed along the x-, y-, and z-axes.

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Osmosis

The process by which solvent molecules pass through a semipermable membrane from a dilute solution into a more concentrated solution.

 

Exothermic

Describes processes that release heat energy.

Meniscus

The shape assumed by the surface of a liquid in a cylindrical container.

Thermodynamics

The study of the energy transfers accompanying physical and chemical processes.

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.

Polyene

A compound that contains more than one double bond per molecule.

Crystalline Solid

A solid characterized by a regular, ordered arrangement of particles.

Ether

Compound in which an oxygen atom is bonded to two alkyl or two aryl groups, or one alkyl and one aryl group.

Metallic Bonding

Bonding within metals due to the electrical attraction of positively charges metal ions for mobile electrons that belong to the crystal as a whole.

Law of Conservation of Matter

There is no detectable change in the quantity of matter during an ordinary chemical reaction.

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.

Supercooled Liquids

Liquids that, when cooled, apparently solidify but actually continue to flow very slowly under the influence of gravity e.g glass.

Diagonal Similarities

Refers to chemical similarities in the Periodic Table of elements of Period 2 to elements of Period 3 one group to the right, especially evident toward the left of the periodic table.

Aromatic Hydrocarbons

Benzene and its derivatives.

Linkage Isomers

Isomers in which a particular ligand bonds to a metal ion through different donor atoms.

 

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.

Evaporization

Vaporization of a liquid below its boiling point.

Crystal Lattice Energy

Amount of energy that holds a crystal together, the energy change when a mole of solid is formed from its constituent molecules or ions (for ionic compounds) in their gaseous state.

D-Orbitals

Beginning in the third energy level, aset of five degenerate orbitals per energy level, higher in energy than s and p orbitals of the same energy level.

 

Fuel Cells

Voltaic cells in which the reactants (usually gases) are supplied continuously.
A voltaic cell that converts the chemical energy of a fuel and an oxidizing agent directly into electriacl energy on a continuous basis.