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An arrangement of elements in order of increasing atomic numbers that also emphasizes periodicity.

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Dubnium

Discovered : at both Berkeley, California, USA, and Dubna, near Moscow, Russia in 1970. Description:A highly radioactive metal which does not occur naturally, and of which only a few atoms have ever been made. It is of research interest only. Origin:The element is named after the Russian town of Dubna.

Density

Density is the ratio b/w Mass and Volume: D=M/V

Critical Mass

The minimum mass of a particular fissionable nuclide in a given volume required to sustain a nuclear chain reaction.

Band of Stability

Band containing nonradioactive nuclides in a plot of number of neutrons versus atomic number.

Outer Orbital Complex

Valence bond designation for a complex in which the metal ion utilizes d orbitals in the outermost (occupied) shell in hybridization.

Polymer

A large molecule consisting of chains or rings of linked monomer units, usually characterized by high melting and boiling points.

Doublet

Two peaks or bands of about equal intensity appearing close together on a spectrogram.

van der Waals' Equation

An equation of state that extends the ideal gas law to real gases by inclusion of two empirically determined parameters, which are different for different gases.

Hard Water

Water containing Fe3+, Ca2+, and Mg2+ ions, which forms precipates with soap.

Isomorphous

Refers to crystals having the same atomic arrangement.

Allotropes

Different forms of the same element in the same physical state.

Common Ion Effect

Suppression of ionization of a weak electrolyte by the presence in the same solution of a strong electrolyte containing one of the same ions as the weak electrolyte.

Evaporization

Vaporization of a liquid below its boiling point.

Ester

A Compound of the general formula R-C-O-R1 where R and R1 may be the same or different, and may be either aliphatic or aromatic.

Unsaturated Hydrocarbons

Hydrocarbons that contain double or triple carbon-carbon bonds.

Actual Yield

Amount of a specified pure product actually obtained from a given reaction. Compare with Theoretical Yield.

First Law of Thermodynamics

The total amount of energy in the universe is constant (also known as the Law of Conservation of Energy) energy is neither created nor destroyed in ordinary chemical reactions and physical changes.

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.

Formula Unit

The smallest repeating unit of a substance. The molecule for nonionic substances

Effective Nuclear Charge

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.