We shall adopt the definition of physics as a science dealing with
the study of the structure and properties of concrete forms of matter-substances and fields, and of the forms of existence of matter
space and time.. It does not reduce
the entire natural science to physics, but it indicates that the basic theoretical foundations of any branch of natural science are of physical nature. Such foundations have already been discovered in
chemistry and today we know that chemistry is concerned with
the study of the structure of the electronic shells of atoms and molecules and of its change in the course of their interactions.