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Antoine Lavoisier wrote the first extensive list of elements containing 33 elements & distinguished between metals and non-metals. Known as the father of modern chameistry
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Gay-Lussac had found in 1808 that when gases
chemically react, the volumes of both the reactants
and the products are in simple ratios. -
John Dalton proposed "Dalton's Law" describing the relationship between the components in a mixture of gases. Atoms are featureless spheres. The only difference between different elements is their weight.
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Amedeo Avogadro was far ahead of his time when he published in 1811 his hypothesis that equal volumes of all gases contain equal numbers of molecules (at the same temperature and pressure).
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Jacob Berzelius developed a table of atomic weights & introduced letters to symbolize elements.
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Johann Dobereiner developed groups of 3 elements with similar properties.
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The time had come for chemists to resolve several questions and
to come to agreement on several conventions. The Chemical Congress debated several key issues. -
John Newlands arranged the known elements in order of atomic weights & observed similarities between some elements.
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Dmitri Mendeleev produced a table based on atomic weights but arranged 'periodically' with elements with similar properties under each other. His Periodic Table included the 66 known elements organized by atomic weights.
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Lothar Meyer develops an early version of the periodic table, with 28 elements organized by valence.
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William Ramsay discovered the noble gases.
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Marie and Pierre Curie isolated radium and polonium from pitchblende.
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Henry Moseley determina el número atómico de cada uno de los elementos y modifico la ley periódica.
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Glenn Seaborg sintetizó los elementos transuránicos (elementos después de uranio en la tabla periódica).
