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Early Stages of the Periodic Table

John Newlands

How they arranged table ­ Newlands recognised that the elements have a repeating
pattern of properties when grouped according to their atomic mass. His table of
elements has eight group and the elements at the top of the table have lower

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minima, the most electro-positive elements appearing at the peaks of the curve in
the order of their atomic weights. Finally, Meyer never came to the idea of predicting
new elements and correcting atomic weights. Only a few months after Mendeleev
published his periodic table of all known elements (and predicted…

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Dmitri Mendeleev

How they arranged table ­ Mendeleev divided elements into eight groups (the
columns) and then listed periods (the rows) of elements. As in Newlands' table, the
elements at the top have lower atomic masses than those lower down. He
concentrated on the chemical properties of elements for this…

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4. Mendeleev's arrangement helped to correct atomic masses of a number of

Disadvantages ­
1. For placing the elements in proper groups, the order of the elements according to
atomic mass was reversed in certain cases. He placed Iodine (127) after Tellurium
(128) Potassium (39) and Ni (58) after…


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