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Antoine Lavoisier
Lavoisier created a list of the 33 known elements -
Johann Dobereiner
Dobereiner grouped the elements according to atomic weight -
Jakob Berzelius
Berzelius creates a table listing certain elements by atomic weight, this is also the first table to represent the elements with letters -
Johann Dobereiner
Dobereiner listed the elements according to his law of triads in which groups of 3 elements were put together with the weight of the middle element is the average of the other two's weights -
John Newlands
Newlands arranged the 62 known elements acording to atomic weight and he found that every element had the same chemical properties after the ones 8 elements before and after it. this was known as the law of octaves -
Dimitri Mendeleev
Mendeleev created a table listing the elements in increasing size of atomic weight and put elements with similar properties underneath each other. the table featured all 66 known elements and left gaps for unknown elements when an elements properties didn't match the one above it -
Lord Rayleigh
Rayleigh discovers argon but it didn't fit into any catagories so it was debated why it was odd and where it should go, eventually it was decided that similar would be discovered later for it to be grouped with -
William Ramsey
Ramsey discovers some more of the noble gases to group with argon -
Marie Curie
Curie discovers radium and polonium the first two radioactive elements in the table -
Henry Moseley
Moseley rearranged Mendeleev's periodic table by ordering the elements by increasing atomic number not atomic mass