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When two or more elements combine to form a compound, they lose their separate identities, and the product has characteristics quite different from those of the constituent elements.
The gaseous elements hydrogen and oxygen, for example, with quite different properties, can combine to form the compound water, which has altogether different properties from either oxygen or hydrogen.
These three alchemical elements, or principles, also represented abstractions of properties reflecting the nature of matter, not physical substances.
The important difference between a mixture and a chemical compound eventually was understood, and in 1661 the English chemist Robert Boyle recognized the fundamental nature of a chemical element.
This article considers the origin of the elements and their abundances throughout the universe.
Lavoisier’s list of elements was established on the basis of a careful, quantitative study of decomposition and recombination reactions.He argued that the four Greek elements could not be the real chemical elements because they cannot combine to form other substances nor can they be extracted from other substances.Boyle stressed the physical nature of elements and related them to the compounds they formed in the modern operational way.The article also discusses the periodic law and the tabular arrangement of the elements based on it.For detailed information about the compounds of the elements, At present there are 118 known chemical elements.
The Greek concept of an element, which was accepted for nearly 2,000 years, contained only one aspect of the modern definition—namely, that elements have characteristic properties.