To understand the essence of this or that science, it is necessary first of all to receive pleasure from knowledge, discovering something new. In this case, it is chemistry. Believe me, she can give the student her real pleasure. And this is not just an accumulation of knowledge with a solid balance of facts. It is very interesting to observe chemical transformations, and illustrative examples in the laboratory can arouse the brightest interest in the student! Because chemistry is the foundation of all substances, those from which the world around us is created. Welcome to this interesting world!
What chemistry studies
Let's see what the subject of study is. In simple terms, chemistry is the science of matter (and, as we know, it occupies a volume and has a certain mass). So, this science explores the structure and properties of substances and all the changes that occur with them. Any of them is either pure, or may consist of a mixture of elements. And the transformation of one into another is called a chemical reaction. A new substance is formed - and this is akin to magic! No wonder in ancient times, alchemists were treated like wizards, believing that they can get gold from other metals.
General classification
Chemistry is a powerful tree with powerful branches - sections of this science. They are quite different in their tasks and methods, but they are closely connected. Chemistry sections :
- Analytical. It talks about how many and what substances are contained in a particular mixture. Makes analysis (quantitative and qualitative) using a wide range of tools.
- Biochemistry. Her subject of study is the chemical reactions that occur in organisms. Metabolism and digestion, respiration and reproduction - all this is the prerogative of this science. Research is being done by scientists at the microscopic or molecular level.
- Inorganic. It is associated with research in the field of inorganics (for example, salts). The structures and properties of these compounds and their individual components are analyzed. It also examines all the elements of the periodic table (excluding carbon, which "got" organic chemistry).
- Organic This is a chemistry that studies carbon compounds. Scientists know a great many (millions!) Of such compounds, but every year they discover and create more and more new ones. They are used in petrochemistry, polymer production, and pharmaceuticals.
- Physical. Here the subject of study is the laws of reactions in relation to physical phenomena. This industry deals with the physical properties and behavior of substances, develops models and theories of action.
Biotechnology
A fairly new industry associated with chemistry and biology. The subject of study is the modification or creation of genetic material (or organisms) for specific scientific purposes. The latest technologies and research in this field are used in cloning, in obtaining new crops, in developing disease resistance and negative heredity in living organisms.
Ancient history
The meaning of the word "chemistry" for human civilization can be learned by following the stages of development of this science. Ever since time immemorial, people, sometimes without realizing it, have used chemical processes to obtain metals from ore, to dye fabrics and leather. Thus, at the dawn of cultural life and the development of the civilized world, chemical doctrine arose.
Middle Ages and Renaissance
And in a new era, alchemy appears. Its main task is the acquisition of the so-called “philosopher's stone”, and the conversion of metals into gold is a passing task. By the way, many historians believe that it was alchemy that gave a huge impetus to the development of chemical science.
In the Renaissance, similar studies began to be used for practical tasks (in metallurgy, the production of ceramics and paints, glassmaking); there is a specialized direction of alchemy - medical.
17-19th century
In the second half of the 17th century R. Boyle for the first time gave a scientific definition of the concept of “chemical element”.
In the second half of the 18th, the transformation of chemistry into science was already coming to an end. By this time, the laws of conservation of mass in chemical reactions were formulated.
In the 19th century, John Dalton lays the foundation for chemical atomism, while Amedeo Avogadro introduces the term "molecule." Atomic molecular chemistry was established in the 60s of the 19th century. A. M. Butlerov creates a theory of the construction of chemical compounds. DI Mendeleev opens the periodic law and the table.
Terminology
A lot of them were affirmed during the whole time of the development of chemistry. The following are only the main ones.
A substance is a type of matter that has certain chemical as well as physical properties. This is a collection of atoms and molecules, which is in the state of aggregation. All physical bodies are made up of substances.
An atom is a chemically indivisible, minute particle of substances. It includes a core and an electronic shell.
And what about the chemical elements? Each of them has its own name, its serial number, location in the periodic table. Today, 118 elements are known in the natural environment (extreme Uuo - ununctii). Elements are identified by symbols that represent 1 or 2 letters of the Latin name (for example, hydrogen - H, Latin name Hydrogenium).