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All orbitals of a given sublevel must be occupied by single electrons before pairing begins.

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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.

Chemical Equation

Description of a chemical reaction by placing the formulas of the reactants on the left and the formulas of products on the right of an arrow.

Photochemical Oxidants

Photochemically produced oxidizing agents capable of causing damage to plants and animals.

Fast Neutron

A neutron ejected at high kinetic energy in a nuclear reaction.


A subatomic particle having a mass of 1.0073 amu and a charge of +1, found in thew nuclei of atoms.

Dipole-dipole Interactions

Attractive interactions between polar molecules, that is, between molecules with permanent dipoles.

Molecular Geometry

The arrangement of atoms (not lone pairs of electrons) around a central atom of a molecule or polyatomic ion.


Potential difference between two electrodes, a measure of the chemical potential for a redox reaction to occur.


An organic ion carrying a negative charge on a carbon atom.

Ionic Geometry

The arrangement of atoms (not lone pairs of electrons) about the central atom of a polyatomic ion.

Heat of Fusion

The amount of heat required to melt one gram of solid at its melting point with no change in temperature. Usually expressed in J/g. The molar heat of fusion is the amount of heat required to melt one mole of a solid at its melting point with no change in temperature and is usually expressed in kJ/mol.

xenon tetrafluoride

A colorless, crystalline compound, XeF4, prepared by heating a gaseous mixture of fluorine and xenon.

Molecular Orbital Theory

A theory of chemical bonding based upon the postulated existence of molecular orbitals.

Ideal Solution

A solution that obeys Raoult's Law exactly.

Ostwald Process

A process for the industrial production of nitrogen oxide and nitric acid from ammonia and oxygen.


Refers to the separation of charge between two covalently bonded atoms.

Lewis Dot Formula (Electron Dot Formula)

Representation of the core of a molecule, ion or formula unit by showing atomic symbols and only outer shell electrons.


Liquid triester of glycerol and unsaturated fatty acids.


Plating a metal onto a (cathodic) surface by electrolysis.

Emission Spectrum

Spectrum associated with emission of electromagnetic radiation by atoms (or other species) resulting from electronic transitions from higher to lower energy states.