Ch 5 Class 10 Science
Three major differences between Mendeleev’s and Modern periodic are
1. Mendeleev Periodic Table – The physical and chemical properties of elements are a periodic function of their atomic masses.
Modern Periodic Table – The properties of elements are a periodic function of their atomic numbers.
2. Mendeleev Periodic Table – The basis of classification was the formula of hydrides and oxides made by the elements.
Modern Periodic Table – The basis of classification is the electronic configuration of the elements.
3. Mendeleev Periodic Table – The noble elements were not included in the table, as they were not discovered at that time.
Modern Periodic Table – It included noble elements in group 18 as a last and separated group.