This document provides definitions for different branches of chemistry: 1. Chemistry is the study of the composition, structure, properties, and changes of matter. 2. Inorganic chemistry deals with inorganic compounds which do not contain carbon-hydrogen bonds. 3. Organic chemistry deals with the chemistry of carbon and living things. 4. Analytical chemistry studies the properties of materials and develops tools for analysis. 5. Physical chemistry applies physics to the study of chemistry, using concepts from quantum mechanics and thermodynamics. 6. Biochemistry is concerned with chemical reactions that occur inside living organisms. 7. Theoretical chemistry uses calculations to explain or predict chemical phenomena.