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

Useful for understanding how matter and energy work, both inside and outside the brain.

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. are made up of different types of atoms and molecules.. These particles are the basic unit of matter and also serve to understand how many Biological processes related to neuroscience, such as depolarization, occur.

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

In this article we are going to see how the main types of chemical bonds are present in nature.

The chemical bond

A chemical bond is understood as that interaction or force that generates that two or more atoms maintain a union based on the transmission of electrons between them. based on the transmission of electrons between them.

The electrons in the outermost shells of the atom are attracted by the electric charge of the surrounding atoms, in particular their nuclei. And although the nuclei repel each other as they are both positively charged, the electrons (negatively charged) of each atom are attracted to the nucleus of the other. by the nucleus of the other.

Depending on the position of both, the electronegativity or difficulty of ionizing the atom and the electronic stability that each atom already possesses, it is possible that the strength of the attraction between electron and nucleus prevents the existence of 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 stable electric charge.

Main types of chemical bonds between atoms

Below you can see what are the three main types of chemical bonding through which different atoms join together to form different molecules. One of the main differences between them are the types of atoms (metallic and/or non-metallic, being the metallic ones not very electronegative and the non-metallic ones very electronegative).

1. Ionic bonding

Ionic is one of the best-known types of chemical bondingIt is formed when a metal and a non-metal (i.e. a component with low electronegativity and one with high electronegativity) are joined together.

The outermost electron of the metallic element will be attracted to the nucleus of the non-metallic element, the latter yielding its electron to the former. Stable compounds are formed, whose bonding is electrochemical. In this union the non-metallic element becomes an anion by finally becoming negatively charged (after receiving the electron), while the 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 bonding tend to require a large amount of energy to melt and tend to be hard, although they can be easily compressed and broken. In general, they tend to be soluble and can be easily dissolved.

2. Covalent bonds

Covalent bonding is a type of bonding characterized by the fact that the two atoms to be bonded possess similar or even identical electronegative properties. The covalent bond assumes that both atoms (or more, if the molecule is formed by more than two atoms) share electrons with each other, without losing or gaining in quantity.

This type of bond is the one that usually forms part of organic matter, such as that which makes up our organism, and is more stable than ionic bonds. Their melting point is lowerThey have a lower melting point, to the point that many compounds are in a liquid state, and are generally not electrically conductive. Within the covalent bonds we can find several subtypes.

Non-polar or pure covalent bond

This refers to a type of covalent bond in which two elements with the same electronegativity level are joined together and whose union does not cause one of the parties to lose or gain electrons, the atoms being 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 usual, the atoms that are joined are of different elements. Both have a similar but not identical electronegativity. but not identical, so they have different electric charges. In this case, neither atom loses electrons, but shares them.

Within this subgroup we also find bipolar covalent bonds, in which there is a donor atom that shares electrons and another or other receptors that benefit from this incorporation.

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

3. Metallic bonding

In metallic bonds, two or more atoms of metallic elements are joined together. This bonding is not due to the attraction between the two atoms to each other, but between a cation and the free and foreign electrons that make it so. 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.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 level of the molecule we can find other types of chemical bonds.. Some of the main and best known are the following.

4. By Van der Waals forces

This type of bonding occurs between symmetrical molecules and acts according to the attraction or repulsion between molecules or to the interaction of ions with molecules. Within this type of bonding we can find the union of two permanent dipolestwo induced dipoles or between permanent and induced dipoles.

5. Hydrogen bonding or hydrogen bridge bonding

This type of bonding between molecules is an interaction between hydrogen and another element of high polarity. In these bonds the hydrogen is positively charged and is attracted to atoms of other elements. is attracted to polar electronegative atoms, generating an interaction or bridge between them.generating an interaction or bridge between the two. Such bonding is considerably weak. An example is found in water molecules.

Bibliographical references:

• Chamizo J. A. (2006). The models of chemistry, Educación Química, 17, 476-482.

• García, A.; Garritz; A. and Chamizo, J.A.. (2009). Chemical Bonding. A constructivist approach to its teaching.