define modern periodic table?
advantage of modern periodic table?

The number of electrons in turn is equal to the number of protons in the nucleus. He suggested that atomic number is a more fundamental property of an element than its atomic mass. When the elements are arranged in the increasing order of their atomic number, most of the defects of Mendeleev's classification get rectified.

The periodic law given earlier is now modified and followed today. It states that "the properties of the elements are periodic functions of their atomic numbers."

The modern periodic table is also known as the long form of the periodic table or the extended form of the periodic table.

In this table, the elements are arranged in the order of increasing atomic numbers in such away that elements with similar properties fall in the same vertical column. These vertical columns are referred to as 'Groups'. There are eight groups, which are further sub-divided into eighteen sub-groups. There are 7 horizontal rows in the periodic table. These are called the periods.