Mendeleev's Table

Mendeleev noted patterns in the combining ratios of elements

The Elements Lithium (Li), Sodium (Na), and Potassium (K) all formed oxides in the ratio of two atoms per oxygen atom: R2O

The Elements Beryllium (Be), Magnesium (Mg), and Calcium (Ca) all formed oxides in

the ratio of one atom per oxygen atom: RO Boron (B) and Aluminum (Al) formed R2O3

Carbon (C) and Silicon (Si) formed RO2

Recognizing the patterns of combining ratios or "valency", Mendeleev created a table organized by placing elements with similar combining ratios in the same group. He arranged the elements within a group in order of their atomic mass.

In 1869, the Russian chemist Mendeleev noted that the repeating patterns of behavior could be arranged in a sequence of elements giving rise to the "Periodic Table" of the elements.

Special thanks to Dr. Paul Karol's "Intro to Modern Chemistry" for providing much of the information on this page.

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Mendeleev's Table

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PERIODIC TABLE OF THE ELEMENTS

About this Resource

Originally this resource, the Periodic Table, was created by Robert Husted at Los Alamos National Laboratory during his time as a Graduate Research Assistant.

The Periodic Table that you are currently viewing was inherited by the Chemistry Division from the Computer Division who provided the laboratory some of the internets first web sites..

This page is being offered as a public service to all those wanting to become more educated in the field of Chemistry. This is an imperfect resource with ambiguities and errors. If you notice something incorrect about our web page we would be grateful for any pointers. We welcome any suggestions or comment at cstsupport@lanl.gov.

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