Chemical bond and the principle of its formation

Chemical bonding is a rather complex concept that has been formed for a long time on the basis of the teachings and ideas about the structure of the atom. Thus, in the XVI-XVII centuries. Were the first attempts to explain the chemical similarity based on corpuscular theory. R. Boyle, thought that the motive power of chemical reactions is the coincidence of particles like the key-lock, that is, the atoms "gathered" and "sorted out", forming new substances. Later in the XVIII century. On the replacement of the mechanical theory comes dynamic, the supporter of which was I. Newton. He believed that the cause of chemical similarity are the forces of attraction of varying intensity. In the ХІХ century. The electrochemical period begins. At this time, the German chemist A. Kekule suggested that the valence is equal to the number of chemical bonds of the atom. Using this statement, they began to depict the structural formulas of molecules in which dashes denoted chemical bonds. These were all preconditions for an explanation of the concept of "chemical bond", which was fully formed only after the discovery of the electron. It was after this that the hypothesis was advanced that substances are formed by the movement or shift of electrons from one atom to another. Over time, this assumption is scientifically confirmed and is used now, arguing that the chemical bond is formed by the interaction of all electrons and all atomic nuclei that are part of the molecules.

The hydrogen atom will help explain the electronic nature of the bond . It is known that it contains one unpaired electron, which is at the first energy level. When two hydrogen atoms converge, the nucleus of one of them begins to attract the electrons of the other, and vice versa. Interaction between atoms occurs between atoms, the distance between them decreases, mutual attraction is counterbalanced by the repulsion of the nuclei. In the molecule that just formed, the electron density is increased. These two electron clouds of elementary particles combine to form one electronic cloud of the molecule. Simply put, a chemical bond is the result of overlapping of electronic orbitals of different atoms due to the interaction of unpaired electrons.

However, not all atoms interact with each other. Thus, electronic shells of inert gases do not overlap; They remain stable. On the basis of this, the Lewis octet rule is formulated, which states that the atoms of all elements in the formation of a chemical bond tend to change the electron shell to the configuration of the nearest inert gas, giving or attaching electrons.

In existing substances, several types of communication are distinguished. So, there is ionic, metallic, covalent, donor-acceptor. For example, the chemical bond of metals exists only for metallic elements. It is formed due to the recoil of 1-2 electrons by each atom, i.e. Next to the particles are "divided" by electrons, which form jelly. Inside this environment are metal ions.

Based on the foregoing, it can be concluded that the chemical bond is an interaction of atoms, which occurs due to the exchange of electrons or their transition from one elementary particle of matter to another.