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Antoine Lavoisier
Classified elements as metals and nonmetals -
Johann Wolfang Dobereiner
Grouped certain elements into groups of three called Dobereiner's triads. Properties of the middle element such as atomic weight was the average of the other two elements. One triad is Lithium, Sodium and Potassium. -
John Newlands
Assembled the Periodic Table of known elements by atomic mass. He noticed that every eight elements showed similar properties which he called law of octaves. -
Dimitri Mendeleev
Father of the modern periodic table. He left gaps for elements that were not yet discovered for which he gave certain names such as EkaAluminium for Aluminium. -
Lothar Meyer
He further refined the periodic table adding more elements as they were discovered. -
Henry Moseley
With the discovery of atomic particles of proton, electron and neutron, he modified the periodic table to be based on atomic number which is the number of protons. This cleared earlier anomalies.