22 October
Bilingual TNPSC Daily Notes on Chemical Bonding and Molecular Structure — ionic, covalent and coordinate bonds, electronegativity, Fajans rules, sigma and pi bonds, VSEPR theory, hybridisation, dipole moment, hydrogen bonding and metallic bonding. 15 key points, detailed notes in English and Tamil, 5 practice MCQs, memory tips and previous-year question patterns for TNPSC Group 1, 2, 2A, 4 and VAO.