The first part of the course will consider the matter from the microscopic point of view, dealing with the principles of the atomic / molecular theory. It then proceeds to describe how matter organizes on a macroscopic scale, treating the general characteristics of the aggregation state. To complete the course,as far as the chemical reactivity, it will be studied the fundamental principles of thermodynamics. The chemical reactivity is further developed through the exposure of the fundamental concepts of organic chemistry and biomolecules. Some topics of the course will be accompanied by conducting problems of stoichiometry.