The main types of chemical bonds: why and how they are formed

The laws by which substances are transformed have long remained an unsolved mystery for man. The classical theory of interatomic ties was proposed rather late - in 1916. Since then, the views of scientists have evolved. In principle, nothing new has been discovered since then, and every schoolboy knows now the types of chemical bonds, which at least tries to learn. For this knowledge, some medieval scientists would sell the soul.

So, there are basic types of chemical bonding and additional ones, called weak interactions. Sometimes they, however, become important, for example, in the formation of the structure of the protein. The main types of chemical bonds include covalent, and also ionic and metallic.

Let's start with covalent ones. It was for them that Gilbert Lewis proposed his first classical theory of chemical bonding. What is the idea of this scientist, actual so far? A covalent bond is formed because in a bound form in a system of atoms, less energy is produced than in atoms one by one. And this is important in chemistry. Each system seeks to get rid of the maximum amount of energy. During the formation of a covalent bond, each of the combining atoms contributes to the creation of the compound. Thus, the external electronic level is filled, particles with a negative charge go "in common use."

The types of chemical bonds are divided into subtypes. For example, a covalent bond is often nonpolar - for example, between atoms of an identical chemical element. So molecules of gases, such as nitrogen, fluorine, hydrogen are formed. The electronic pair "in common ownership" is geometrically approximately in the middle. Although this is difficult to talk about, because research shows that it is almost impossible to predict the path of an electron.

Another thing is the connection between the atoms of different chemical elements. For example, in the bond between fluorine and hydrogen atoms, the total vapor is spatially closer to one of the atoms, namely, to fluorine. This connection has a polar name.

But not always atoms "honestly contribute equally" in the formation of contributions. It also happens that one of the atoms provides two electrons at once, and the second - an orbit for this pair, which goes into general use. How to name the nature of this compound? Donor-acceptor type of connection. The ammonium ion can be a good example. Three hydrogen atoms participate in ordinary polar covalent bonds, and the remaining free pair of electrons of nitrogen can be transferred to sharing with another hydrogen atom. Still, such a connection is considered to be covalent, because regions of high electron density are located between atoms.

What other types of chemical bonds exist? An ionic bond exists between particles that have different charges. The force of attraction of the elements of this connection depends only on the distance that separates them, and on the orientation - does not depend. Where do you find such connections? First of all, in crystalline substances - alkalis, carbides, salts, nitrides, basic oxides. If the cation and anion are similar in size, then the bond becomes particularly stable. Some chemists tend to regard this type of connection as the extreme case of a polar covalent one. But this is a controversial issue, because the electron density still does not fully approach the negatively charged cation.

The metal bond is usually very unlike other types of chemical bonds. Because it is not only a unique chemical, but also a unique physical phenomenon. The fact is that electrons form all the atoms in the formation of the bond. And their directional motion explains the possibility of high electrical conductivity in metals. So every atom in the lattice site contributes to the chemical bond.

As it became clear from the description above, the types of chemical bonds differ precisely by the principle of their formation.