Question

Differentiate between the arrangement of elements in Mendeleev’s periodic table and Modern periodic table.

Answer 1

1. modern periodic table was arranged on the basis of atomic no. but mendeleev's periodic table was based on atomic masses

2. In modern periodic table, places are there for isotopes

Answer 2

Differences are-
1.mandeleev periodic table was based upon the atomic mass of the elements whereas the modern periodic table was based on the atomic numbers of the elments.
2.there were more number of elements in modern periodic table as compared to mandeleev periodic table .
3.mandeleev periodic table does not constitutes isotopes of the same elements in its arrangement whereas isotopes were succesfully Classified in modern periodic table.
4.mandeleev periodic table does not give hydrogen a specific place whereas it was succesfully placed in modern periodic table.