Modern periodic table removes various anomalies of Mendeleev’s periodic table as follows:

● In the modern periodic table, elements are arranged in the increasing order of their atomic number.

● In the modern periodic table, there was no problem of the place of isotopes. All isotopes of the same element have different atomic masses, but same atomic number. Hence, they can put at one place in the same group of the periodic table.

● Element having same valence electron are kept in the same group.

● In the modern periodic table, position of hydrogen became clear. It is kept in the group with the elements of same valence electrons.