What are the basic differences between Mendeleev's periodic table and modern periodic table?

What is the basic difference in approach between Mendeleev's periodic table and modern periodic table?

Distinguish between: Mendeleev's periodic table and Modern periodic table

What is the difference between Mendeleev's periodic law and modern periodic law?

What is the basic difference between Mendeleev's periodic table been overcome in the modern periodic table ?

What is a period in modern periodic table ?