Mendeleev’s periodic table contains 63 elements.
Mendeleev Periodic Table
Mendeleev claimed the famous periodic law that “Element properties are a periodic function of their atomic weight.” Mendeleev placed elements in the order of their atomic weights in the form of a table known as the Periodic Table of Mendeleev.
Mendeleev initially arranged elements, one below the other, in the order of increasing atomic weight. Elements having similar properties are placed nearby. Elements with similar properties are found in the same horizontal row. Mendeleev’s original periodic table, published in 1869.