Chemistry studies the composition, properties, and transformations of substances, as well as the phenomena that accompany these transformations: "Chemical science considers the properties and changes of bodies. The composition of bodies. According to Mendeleev, chemistry is teaching about elements and their compounds. It is closely related to other natural sciences: physics, biology, geology. Many sections of modern science emerged at the intersection of these sciences: physical chemistry, geochemistry, biochemistry. Chemistry is also closely related to other branches of science and technology. Mathematical methods are widely used and calculations and modeling of processes on electronic machines are used. They are usually divided into mixtures and pure substances. Among the latter are simple and complex ones. Simple substances are known to be more than 400, and complex substances are much more: several hundred thousand inorganic substances and several million organic substances. General chemistry considers the basic chemical concepts as well as the most important regularities related to chemical transformations. This section includes the basics of various sections of modern science: "physical chemistry, chemical kinetics, electrochemistry, structural chemistry, etc. Inorganic chemistry studies the properties and transformations of inorganic (mineral) substances. Organic Chemistry from Organic Properties and Transformations. The Role of Chemistry in Industry and Agriculture. At all times, chemistry serves man in his practical activity. In ancient times there were crafts based on chemical processes: production of metals, glass, ceramics, dyes, etc. Chemistry plays an important role in modern industry. Chemical and petrochemical industries are the most important branches of industry, without which the functioning of the economy is impossible. Among the most important products are acids, alkalis, salts, mineral fertilizers, solvents, oils, plastics, rubber and rubber, synthetic fibers and many others. At present, the chemical industry produces several tens of thousands of products, and chemical products and processes in the energy sector, which uses the energy of chemical reactions, play an extremely important role. For energy purposes, many oil products (gasoline, kerosene, fuel oil), hard and brown coal, shale, peat are used. The development of many branches of industry is connected with chemistry: metallurgy, mechanical engineering, transport, building materials industry, electronics, light industry, food industry - this is an incomplete list of branches of economy, which widely use chemical products and processes. Many industries use chemical methods, such as catalysis (process acceleration), chemical treatment of metals, and corrosion protection of metals. Chemistry plays an important role in the development of the pharmaceutical industry: most of all medicines are synthetically produced.
Chemistry is extremely important in agriculture, which uses mineral fertilizers, pest control agents, plant growth regulators, chemical additives and preservatives for animal feed and other products. The use of chemical methods in agriculture has led to the emergence of several related sciences, such as agrochemistry and biotechnology, the achievements of which are now widely used in the production of agricultural products. The rapid development of industry, including the chemical industry, has created a serious problem: the need to reduce its negative impact on the environment. science, which studies the relationship of mankind with the environment, has been called ecology. Ecology has a close connection with chemistry. On the one hand, the chemical impact on the environment causes great damage, but on the other hand, it is possible to prevent the degradation of nature by using chemical methods.
Chemistry and the chemical industry are among the most significant sources of environmental pollution. Other most environmentally unfavorable industries are ferrous and non-ferrous metallurgy, road transport and energy (mainly thermal power plants). Only a sound knowledge and use of chemistry will contribute to increasing the wealth of the country.