Notes on Periodic Classification of Elements (BSc and Integrated Standard)
Notes on Periodic Classification of Elements Disadvantages of Mendeleev’s Periodic Table: 1. Position of hydrogen: It has been confirmed that hydrogen has many characters which match with halogen elements too. But it is only placed in Group IA. Thus position of hydrogen is not clear. 2. Position of isotopes: Since in Mendeleev’s periodic table elements have been arranged according to their atomic masses, isotopes (more than one element) are placed at a one place which is confusing. 3. Position of the isobar: Since in Mendeleev’s periodic table elements have been arranged according to their atomic masses, different elements having different atomic numbers but same mass number (isobars) are placed at one place which is again confusing. 4. No attempts were made to separate metals from non-m...