Introduction, size effects, radius ratio rules- calculation of limiting radius ratio values for coordination number 3,4 ,6 and 8; close packing; classification of ionic structures, (ionic compounds of the type AX (ZnS, NaCl, CsCl) and AX₂ (CaF₂-Fluorite)), limitations of radius ratio rule; calculation of lattice energy, factors affecting lattice energy, the Born Haber cycle and its application; solvation energy and solubilities of ionic substances; stoichiometric and non stoichiometric defects.

The Lewis theory, octet rule, explanations for the failure of octet rule,exceptions to octet rule; valence bond theory (Heitler and London approach) and its limitations; resonance; directional character of covalent bond, various types of hybridization ( sp, sp², sp³, sp³d,sp³d², dsp², sp³d³) and shapes of molecules; VSEPR theory,  isoelectronic principle, examples using VSEPR theory, polarizability of ions, Fajan’s rule and consequences of polarization, dipole moment and percentage ionic character in covalent compounds ( electronegativity difference and dipole moment method), bond energy and bond length.

Introduction, LCAO approach, combination of orbitals (s-s, s-p, p-p, non-bonding combination of orbitals), examples of molecular orbital treatment for homonuclear diatomic molecules– H₂⁺, H₂, He₂, B₂, C₂, N₂, Be₂, O₂, O₂⁺¹, O₂^-1, O₂^-2, F₂, examples of molecular orbital treatment for heteronuclear diatomic molecules - NO, NO⁺, CO, CO⁺, CO^-,  CN, CN^-  molecule, comparison of VBT and MOT.

Multicentred bonding in electron deficient molecule; general properties of metals– conductivity, lustre, malleability, ductility, crystal structures; theories of bonding in metals – free electron theory, valence bond theory and band theory – conductors, insulators and semi-conductors; superconductors.

Van der Waal’s forces: ion-dipole forces, dipole-dipole interactions, induced dipole interactions, instantaneous dipole – induced dipole interactions, repulsive forces.

Hydrogen bond: types, theories and properties of H-bond, effects of H-bond on physical properties.