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Q. What is the basis of a periodic table?
A. Chemical element information in a tabular arrangement in an atomic number order with indication of the beginning and end of periods based on the similarities of the elements before and after in the sequence. In general terms, the 2008 Wikipedia guide is "..certain properties of elements repeat periodically when arranged by atomic number". In the common flat table a Period starts at the left side and ends at the right side, and the similar elements are more or less in columns, called Groups.
Details of answer;
the periodic table is one of the most powerful icons in science; a single document that captures the essence of chemistry in an elegant pattern.
Combinations of 26 letters make up every word in the English language.
Similarly, all material things in the world are composed of different combinations of about 100 different elements. An element is a substance that cannot be broken down into simpler substances through ordinary chemistry--it is not destroyed by acids, for example, nor changed by electricity, light, or heat.
Discovery of the 92 natural elements is one of the greatest achievements of human intellectual curiosity.
Although philosophers in the ancient world had a rudimentary concept of elements, they were incorrect in identifying water, for example, as one. Today it is common knowledge that water is a compound, whose smallest unit is a molecule. Passing electricity through a molecule of water can separate it into two atoms of hydrogen and one atom of oxygen, each a separate element.
The ancient concept of elements jibed with today’s in noting that elements had characteristic properties. Just as people not only look different from each other but also interact differently with others, so elements have both physical and chemical properties. Some elements form shiny solids, for example, that react readily and sometimes violently with oxygen and water. The atoms of other elements form gases that scarcely interact with other elements.
Following the determination (1868) of weights of elements (in comparison to an atom of hydrogen, the lightest element) by Stanislao Cannizaro and their arrangement (1862) by Alexandre-Emile de Chancourtois in a spiral on a rotating cylinder defining the periodic nature of the elements, Meyer and Mendeleev developed (1869) the flat periodic table, providing a more convenient framework for display of modern chemical information.
Scientists had identified over 60 elements by that time, and elements were considered the most basic particle of matter. The building blocks of atoms (electrons, protons, and neutrons) were discovered only later.
Resources;
World of Elements, Elements of the World; Quadbeck-Seeger, the Periodic Table; Scerri, chemeducator.org, aip.org, corrosion-doctors.org
