History of the periodic table - As much as an A level student needs to know.

• Aristotle: Theory of four elements, Fire, Water, Earth and Air. 330 BC




• Antoine Lavoisier: Wrote the first extensive list of elements containing 33 elements.



• Distinguished between metals and non-metals. 1770 - 1789



• Jons Berzelius: Developed a table of atomic weights. Introduced letters to symbolize elements. 1828



• Johann Dobereiner: Developed "Triads". Groups of 3 elements with similar properties. 1829



• John Newlands: Arranged the known elements in order of atomic weight, and proposed the Law of Octaves. 1864



• Lothar Meyer: Compiled a periodic table of 56 elements based on the periodictivity of properties such as molar volume, then arranged in order of atomic weight. 1869



• Demitri Mendeleev: Produced a table based on atomic weights, but arranged periodically with elements with similar properties under each other, and left gaps for elements not yet discovered. 1869



• William Ramsay: Discovered the Noble Gases. 1894