Modern periodic table represents an organised array of chemical elements, arranged in an informative way. These elements were classified based on a distinct number that each of the element possesses and holds a fixed position in the Periodic Table. It was arranged by Russian Chemist and inventor Dmitri Mendeleev. This arrangement made it possible to predict chemical and physical behaviour of elements viz how it would react with other elements, what kind of compounds it would form, and what sort of physical properties it would have. In the arrangement, the horizontal rows were termed as periods and vertical columns are termed as groups. According to IUPAC, these groups range from 1 to 18 and there are seven periods.