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In 330BC, Artistotle came up with the idea of the four elements: fire, water, earth, air.
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In 360BC, Plato comes up with the term elements (stoicheia).
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Democritus proposed the idea of the atom, making up all matter, in 440BC.
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In 1605, Sir Francis Bacon published "The Proficience and Advancement of Learning" containing a description of what is now known as the scientific method.
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Hennig discovered the first element, phosphorus, through scientific inquiry.
April 15, 2010, History of the Development of the Periodic Table of Elements. Viewed on 20/08/2012 at http://www.bpc.edu/mathscience/chemistry/history_of_the_periodic_table.html -
Robert Boyle published "The Sceptical Chymist" in 1661, identifying the difference between Chemistry and Alchemy. It also contained the earliest ideas of atoms, molecules and chemical reactions, beginning the history of modern chemistry.
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Joseph Black in 1754, isolated carbon dioxide he called "fixed air".
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Henry Cavendish discovered hydrogen as a colourless, odourless gas that burns and creates explosion when it comes into contact with air
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Antoine Lavoisier wrote the first 33 elements and categorised them into metals and non-metals.
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proposed "Dalton's Law" defining the relationship between the components of a mixture of gases.
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Berzelius created a table of atomic weights and introduced letters to symbolise elements.
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Dobreiner created groups of 3 elements with similar properties.
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The first to make use of the atomic weight of elements, arranging elements according to their atomic weight with similar elements occuring in regular places.
April 15th 2010, History of the Development of the Periodic Table of Elements. Viewed on 20/08/2012 at http://www.bpc.edu/mathscience/chemistry/history_of_the_periodic_table.html -
John Newlands arranged known elements in order of atomic weight and examined similarities between some of them.
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Lothar Meyer developed an early version of the periodic table with 28 elements organized by power.
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Mendeleev produced a table using atomic weights and arranging them periodically, based on their similarities. This table included 66 known elements organized by their atomic weight and chemical valency. Predictabilities like so, simplifies the study of chemistry. One study of a group makes another study easier due to chemical reactions and properties
being so similar.
http://www.bpc.edu/mathscience/chemistry/history_of_the_periodic_table.html
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Sir William Ramsay discovered the noble gases.
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Marie and Pierre Curie secluded radium and polonium from pitch-blende (a mineral source of uranium).
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In 1900, Ernest Rutherford discovered the source of radioactivity as decomposing atoms.
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Henry Moseley determined the atomic number for each of the elements and made a few modifications to "The Periodic Law", realising atoms arranged according to increasing atomic number, the problems Mendeleev had, no longer existed.
The modern periodic table is still based on atomic numbers, thanks to Moseley's work.
http://www.history-timelines.org.uk/events-timelines/19-periodic-table-timeline.htm
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McMillan and Abelson identified and discovered neptunium, the lightest and manufactured and transuranium element, found in the products of uranium fission (seperation).
April 15th 2012, History of the Development of the Periodic Table of Elements. Viewed on 20/08/2012 at http://www.bpc.edu/mathscience/chemistry/history_of_the_periodic_table.html -
In 1940, Glenn Seaborg created transuranic elements ( the elements after uranium in the periodic table).
http://www.history-timelines.org.uk/events-timelines/19-periodic-table-timeline.htm
