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Pauli Exclusion Principle

Rationalizing The Periodic Law

For more than half a century, chemists had known that the chemical elements display a regular pattern of properties, a discovery originally announced as the periodic law by the Russian chemist Dmitri Mendeleev (1834-1907) in about 1869. The Pauli exclusion principle provided important theoretical support for the periodic law. When a chart is made showing the electronic configuration of all the elements, an interesting pattern results. The elements have one, two, three, four (and so on) electrons in their outermost orbital in a regular and repeating pattern. All elements with one electron in their outermost orbital, for example, occur in column one of Mendeleev's periodic table. They have similar chemical and physical properties, it turns out, because they have similar electronic configurations.


Resources

Books

Miller, Franklin, Jr. College Physics. 5th ed. New York: Harcourt Brace Jovanovich, 1982.


David E. Newton

KEY TERMS

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Electronic configuration

—The arrangement of electrons in an atom.

Orbital

—A group of electrons in an atom that all have the same primary and secondary quantum numbers.

Periodic law

—A statement that the physical and chemical properties of the chemical elements repeat themselves according to an orderly and periodic pattern.

Shell

—A group of electrons in an atom that all have the same primary quantum number.

Additional topics

Science EncyclopediaScience & Philosophy: Evolution to FerrocyanidePauli Exclusion Principle - Historical Background, The Exclusion Principle, Electronic Configurations, Rationalizing The Periodic Law