de-Broglie wave equation and Heisenberg's uncertainty principle with numericals. Relation between Spherical polar cordinates and Cartesian coordinates. Shape of orbital predicted on the basis of Angular wave function. About modern periodic table and it merits and drawbacks of old periodic table. Effective nuclear charge, shielding effect and calculation of shielding constant. Ionisation energy and its factors and its periodicity in different groups and period in the periodic table. Electron affinity and its factors and its periodicity in different groups and period in the periodic table. Electronegativity and its factors and its periodicity in different groups and period in the periodic table. Different methods to calculate electronegativity. Application of electronegativity. Some theories like Lewis theory, Sidgwick-Powell theory, VSEPR theory, Valence bond theory and Molecular orbital theory to explain the formation of bond and shape of molecules.