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First Attempts 1783
Antoine-Laurent de Lavoisier published a list with 33 elements, and grouping them into gases, metals, non-metals and earths. He believed that these 'simple substances' could not be broken down further. -
Triads 1817-1829
Johann Wolfgang Döbereiner began to formulate a way to classify the elements. In 1829, he formed elements into groups of three, each having similar properties. The atomic weight of the middle element was almost exactly the average of the weights of the other two elements. -
Telluric Helix 1862
Alexandre-Emile Béguyer de Chancourtois was able to notice the periodicity of the elements. When they were ordered by atomic weight, similar elements occurred at regular intervals. He created a table named Vis tellurique, after the element tellurium which was near the centre of the diagram.
He arranged the diagram on a cylinder, those elements with similar properties lined up vertically. -
Octaves 1864
John Newlands classified 62 known elements into seven groups, these groups were based on the physical properties of the elements. He noted that many pairs of similar elements existed, and assigned all the elements written an atomic number. The importance of his analysis was not recognised at first, as it was ridiculed for its likening between the periodicity of eights and a musical scale. It was eventually recognised in the following century, and described him as the “discoverer of Periodic Law -
Modern Table 1869
Dimitri Mendeleev arranged the elements by atomic mass, which was corresponding to relative molar mass. Mendeleev stated that eight rules about the elements and the table, including ‘The elements, if arranged according to their atomic mass, exhibit an apparent periodicity of properties.’ He was able to arrange the table very precisely, with the table being the one similar to the one we use today. With the table, it enabled the prediction of unknown or new elements, and was able to point out that
