What is chemistry? Is most commonly asked question.
So, following is most comprehensive and simple definition of chemistry.
“Chemistry is study of composition of matter, properties of matter, changes in matter & rules/principles, under which changes take place in matter”.
Chemistry is the study of quantum mechanics, micro mechanics. Macroscopic examination of large (bulk) matter. Chemistry is only concerned with Thermodynamics and Fluid Mechanics; the remaining chemistry has completely micro-dimensions. The transition between micro-macro properties is provided by another branch of chemistry called Statistical Mechanics.
Although there is no clear boundary between physics and chemistry, it can be said that in general 80 percent of Physics and Chemistry are exactly the same; for example, it is not important for the chemist to study the planets mechanically or the projectile motion of a ball, and for the physicist, the content of organic chemistry has no meaning.
Considering that there are about 3.5 million organic and about 2 million inorganic compounds, the science of chemistry involves the study of about 6 million compounds, many sub-groups that group related compounds, systems, methods and objectives to systematically develop information and activities on this subject, and to develop a systematic one. Branches: Analytical chemistry, Biochemistry, Inorganic chemistry (Inorganic chemistry), Organic chemistry, Physical chemistry, Quantum mechanics, Statistical mechanics, Quantum chemistry, Nuclear chemistry, Solid state chemistry, Liquid state chemistry, Plasma chemistry, Particle chemistry (High energy chemistry) are mainly chemistry branches. When we talk about chemistry, we should first think of the science that examines all substances.
Chemical Engineering (based on its name) should not be considered as a chemical sector. Chemistry does not have a sector; Chemical Engineering is concerned with the production, control and design of production schemes of chemical substances in the industry. The chemical engineer has nothing to do with the work done with the chemist. Chemical engineering should be considered as a kind of industrial engineering.