The 5 types of chemical bonds: this is how matter is composed

The cells of our body, the air, the water, the different minerals... each and every one of the elements that surround us are made up of different types of atoms and molecules. These particles are the basic unit of matter and, in addition, they serve to understand how many biological processes related to neurosciences occur, such as depolarization.

However, in order to form something as complex as a living organism or the various compounds or materials that we observe in our day to day it is necessary that the atoms are grouped and related in some way. Chemistry has studied the composition of matter, including the elements that allow the different atoms to bond. These are the so-called chemical bonds.

In this article let's see what the main types of chemical bonds are like present in nature.

• Related article: "The 15 types of energy: what are they?"

The chemical bond

By chemical bond is understood that interaction or force that causes two or more atoms to maintain a bond based on the transmission of electrons between the two.

The electrons in the outermost shells of the atom are attracted by the electrical charge of the atoms that surround it, specifically its nucleus. And although the nuclei repel each other as they both have a positive charge, electrons (negatively charged) in each of the atoms are attracted by the core of the other.

Depending on the position of both, the electronegativity or difficulty of ionizing the atom and the electronic stability that already possess each atom, it is possible that the force of the attraction between electron and nucleus prevents there is a repulsion between atoms. A chemical bond will be created in which one of the atoms will lose electrons and the other will gain them, achieving a final state in which the set of the two atoms reaches a level of electrical charge stable.

• Related article: "The 9 postulates of Dalton's atomic theory"

Main types of chemical bonds between atoms

Below you can see what are the three main types of chemical bond through which the different atoms join to form the different molecules. One of the main differences between them is the types of atoms that are used (metallic and / or non-metallic, the metallic ones being little electronegative and the non metallic ones a lot).

1. Ionic bond

The ionic it is one of the best known types of chemical bond, being the one that is formed when a metal and a non-metal are joined (that is, a component with little electronegativity with one with a lot).

The outermost electron of the metallic element will be attracted to the nucleus of the non-metallic element, with the second giving the electron to the first. Stable compounds are formed, the union of which is electrochemical. In this union, the non-metallic element becomes an anion. finally being negatively charged (after receiving the electron), while metals become positively charged cations.

A typical example of ionic bonding is found in salt, or in crystallized compounds. Materials formed by this type of bond tend to require a great deal of energy to melt and are often hard, although they can easily compress and break. In general they tend to be soluble and can be easily dissolved.

2. Covalent bonds

The covalent bond is a type of bond characterized in that the two atoms to be joined have similar or even identical electronegative properties. The covalent bond assumes that both atoms (or more, if the molecule is made up of more than two atoms) share electrons with each other, without losing or gaining in quantity.

This type of bond is the one that is usually part of organic matter, such as the one that makes up our body, and they are more stable than ionic ones. Its melting point is lower, to the point that many compounds are in a liquid state, and are not generally conductive of electricity. Within the covalent bonds we can find several subtypes.

Nonpolar or pure covalent bond

It refers to a type of covalent bond in which two elements with the same level of electronegativity are joined and whose union does not cause one of the parts to lose or gain electrons, being the atoms of the same element. For example, hydrogen, oxygen or carbon are some elements that can join atoms of the same element to form structures. They are not soluble.

Polar covalent bond

In this type of covalent bond, actually the most common, the atoms that are joined are of different elements. Both have similar electronegativity although not identical, so they have different electrical charges. Also in this case, electrons are not lost in any of the atoms, but they are shared.

Within this subgroup we also find the bipolar covalent bonds, in which there is an atom donor that shares electrons and one or more other receptors that benefit from such incorporation.

Things as basic and essential for us as water or glucose are formed from this type of link.

3. Metallic bond

In metallic bonds, two or more atoms of metallic elements are joined together. This union is due not to the attraction between the two atoms, but rather between a cation and the electrons that have been left free and alien, making it such a thing. The different atoms form a network around these electrons, with repeating patterns. These structures tend to appear as solid and consistent elements, deformable but difficult to break.

Likewise, this type of bond is linked to the electrical conductivity of metals, as their electrons are free.

Chemical bonds between molecules

Although the main chemical bonds are the above, at the molecule level we can find other modalities. Some of the main and best known are the following.

4. By forces of Van der Waals

This type of union occurs between symmetric molecules and acts as a function of the attraction or repulsion between molecules or the interaction of ions with molecules. Within this type of union we can find the union of two permanent dipoles, two induced dipoles or between permanent and induced dipoles.

5. Hydrogen bonding or hydrogen bonding

This type of bond between molecules occurs an interaction between hydrogen and another element of high polarity. In these bonds the hydrogen has a positive charge and is attracted to polar electronegative atoms, generating an interaction or bridge between the two. This bond is considerably weak. An example is found in water molecules.

Bibliographic references:

• Chamizo J. TO. (2006). The models of chemistry, Chemical Education, 17, 476-482.

• García, A.; Garritz; TO. and Chamizo, J.A.. (2009). Chemical bond. A constructivist approach to his teaching.