This textbook has been specifically developed on the directives of National Education Policy (NEP 2020) and is as per latest curriculum of B. Sc. Chemistry (First Semester) for the Lucknow University. Maintaining the traditional approach to the subject, the book comprehensively covers important topics such as Atomic Structure, Periodic Properties and Classification, Covalent Bond and Weak Interactions, Ionic Bond and Ionic Solids, s-Block Elements, p-Block Elements, and Noble Gases have been presented systematically to help students in achieving solid conceptional understanding and learn experimental procedures.