Published by Dmitri Mendeleev in 1869, the periodic table is an arrangement of the chemical elements based on their atomic number, electron configurations, and recurring chemical properties. Ordered by increasing atomic number, the table consists o f 18 columns and 7 rows. The table is used widely in chemistry and other sciences as a framework for chemical behaviour analysis.
Dmitri Mendeleev developed his table to illustrate the periodic trends of the known elements and to predict the properties of the unknown ones. Many of Mendeleev’s predictions have since been proven correct with the discovery of more elements since his death in 1907.