History of Chemical element

	Revision 12 . . October 8, 2001 7:05 am by Sjn28
	Revision 11 . . October 8, 2001 3:01 am by Vicki Rosenzweig [clarification of compounds]

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Difference (from prior major revision) (no other diffs)

Changed: 1,2c1,3

A chemical element (sometimes called simply element) is a unique type of atom characterized by the number of protons in its nucleus. In

A chemical element (sometimes called simply element) is a class of atoms with the same number of protons in the nucleus. For example, all atoms with 6 protons in their nuclei are atoms of the chemical element carbon, and all atoms with 92 protons in their nuclei are atoms of the element uranium. In

Changed: 6c7

The official names of the chemical elements are decided by the International Union of Pure and Applied Chemistry.

The official names of the chemical elements are decided by the International Union of Pure and Applied Chemistry. Chemical elements are also given a unique chemical symbol, often based on the name of the element, though possibly not in English (for example, carbon has chemical symbol 'C', and sodium has chemical symbol 'Na' after the Latin natrium). Chemical symbols are understood internationally when element names might need to be translated.

Changed: 8c9

Chemicals that are not elements are called compounds?. These include water, metal alloys, salts, oxides, and organic compounds.

Chemicals that are not pure elements may be mixtures (such as metal alloys) or pure compounds (such as water, salts, oxides and organic compounds).