Covalent Bonding

A chemical bond formed between the atoms due to the sharing of electrons between them is called a covalent bond. The pair of electrons that form a part of this sharing are called shared pairs or bonding pairs. The bond formed because of the attractive and repulsive forces of the atoms, when they share electrons, is called covalent bonding. It basically is the interatomic linkage that leads to the sharing of electrons between the atoms. The binding occurs due to the presence of electrostatic attraction of the nuclei of their elements. The energy required for the binding and sharing to take place should lower as compared to that of widely separated atoms as it becomes easy for the atoms to share the electrons and form a bond.

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Covalent bonding is an important part of the entire Chemistry. While bond formation is still an arguable discussion as no one knows how that happened for the very first time, its physical origin is still unknown even with the availability of quantitative molecular structure, increasing accurate calculations and many other factors. Hence, bonds and covalent bonds and bonding are a major part of Chemistry. 

It is essential to understand chemical bonds before we understand and learn about covalent bonds and their types and forms. 

What is a chemical bond? 

A chemical bond is a semi-permanent attachment between atoms or groups of atoms in a molecule. It is formed by the attractive forces between the atoms. Once the bond is formed, the atoms of the elements work as a unit. Let us now discuss the types of bonds in chemistry.

TYPES OF BONDS

Substances come together to form compounds with the force of chemical bondings. These compounds can be identified by the type of bond that  has been formed between them. Types of chemical bonds vary in structure and properties, volume, mass, strength, number of electrons required to form and other factors as well. 

Hence, there are majorly four types of bonds formed in chemistry, namely:

• Ionic Bonds

• Covalent Bonds 

• Hydrogen Bonds

• Polar Bonds

1. Ionic Bonds

    Atoms with the largest electronegativity differences, i.e., the force that helps the metals bond with nonmetals, the bonding interaction is called ionic. Once the electrons have been transferred and completely done, both the metal and nonmetal are considered ions. The ions then form an ionic compound. The bond formed between those ions is called ionic bonds.

In ionic bonds, the metal loses electrons to form a positively charged cation, while the non-metal accepts electrons to become a negatively charged anion. Ionic bonding is formed because the metal has fewer electrons in its outermost orbit. by losing the electrons, it reaches the noble gas configuration, thus satisfying the octet rule.

2. Covalent Bonds

    The easiest way to understand what a covalent bond is that it is a bond formed by an attractive force between atoms. The electrons are shared. This type of bonding occurs between two atoms of an equivalent element or elements  of one another within the table. This type of bond can generally be seen among non-metals, but it also occurs between metals and nonmetals. Metals alone never form covalent bonds.

If atoms have the same electronegativities, i.e. They have the same affinity for electrons, covalent bonds are most likely to occur. Molecules with covalent bonds include inorganic substances like hydrogen, nitrogen, chlorine, water and ammonia, alongside all the organic compounds.

In structural representation of compounds, the bonds are shown with the help of lines between the atoms. A single line indicates a single covalent bond between two atoms, double lines means a double covalent bond between two atoms, and triple lines mean a triple covalent bond is formed in carbon monoxide.

Example:

Lewis Formulation of Covalent Bonds

We have learned about how ions come together to form ionic bonds. But an exciting way is to know how atoms come together and form covalent compounds. American chemist G.N. Lewis was instrumental in giving the theory of covalent bonding. He came up with an interesting idea about how we can imitate the formation of covalent bonds on paper. He described the formation of such bonds as a result of specific properties of certain atoms to mix and attain noble gas configuration.

The best example to demonstrate a covalent compound is by studying the atomic structure of Hydrogen Chloride, which forms a polar covalent bond. G.N. Lewis indicates the formation of a bond between two elements through a line. The pair of electrons that form the bond is called a bonding pair. Rest all the pairs of electrons are called lone pairs since they do not contribute to bond formation.

A more complex compound called hydrogen chloride can also be formed using Lewis’s bond structure.

• First, the available valence electrons are counted, and the chemical symbols representing the elements are then placed.

• Next, one bonding pair is added between each linked pair of atoms to get it connected.

• The remaining electrons are then added to the atoms so that each atom completes its octet configuration.

• Finally, each bonding pair or the compound so formed is represented by a dash.

3. Hydrogen Bonds

    Hydrogen bond is an attractive and special bond that can occur between different molecules. Since these bonds are weaker than ionic and covalent bonds, which makes it easier to break them.  However, an outsized number of those bonds can exert a robust force. Hydrogen bonds are formed due to unequal charge distribution on a molecule. These molecules are called polar molecules.

If we look at the water molecule, we will find that the oxygen atom shares electrons with two different hydrogen atoms. So, in total, this molecule has 10 protons and electrons – 8 from oxygen and one each from the hydrogen atoms. 

4. Polar Bonds

     A polar bond may be a chemical bond during which the electrons forming the bond are unequally distributed. In other words, the electrons spend more time at one part of the atom than at the other. Polar bonds include properties of both- pure covalent bonds and ionic bonds. They are formed when the electronegativity difference between the cation and the anion is between 0.4 and 1.7.

Conclusion:

 Everything around us is made up of compounds. We are basically surrounded by chemistry, be it the water we drink, the air we breathe, the food we eat, the energy that is transformed from one phase to another. Everything is chemistry. Hence, it becomes a little important to know about the same. In this article, we studied chemical bonds, their types and what compounds are formed due to the presence of which bonds. Chemical bonds, just like our everyday life, are important to hold things together and make them look as they are supposed to be. Thus, every bond is important so that the elements are exactly as they should be and are not destroyed.