Chemistry 9 th Short questions. Qno:1 Define Chemistry? Ans: The branch of science deals with the study of composition,structure,properties and reactions of matter is called chemistry. Application of Chemistry : The development of chemical industry has also generated toxic wastes , contaminated water and polluted air around us . 1.1 Branches of Chemistry 1.1 Physical Chemistry Physical Chemistry is defined as the branch of chemistry that deals with the relationship between the composition and physical properties of matter along with the changes in them. 1.1.2 Organic Chemistry Organic Chemistry is the study of covalent compounds of carbon and hydrogen (hydrocarbon) and their derivatives . 1.1.3 Inorganic Chemistry Inorganic Chemistry deals with the study of all elements and their compounds excep...