Chemical Bonding | It’s Definition, Types and Examples

Chemical Bonding

In this article at Home Learning Hub-Great Home Learning For All we are going to discuss chemical bonding, it’s definition, types and examples including introduction, ionic bond, covalent bond, coordinate covalent bond and metallic bond so let’s get started.

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“Chemical Bonding, It’s definition, Types and Examples”

Outline:

Introduction

Types of Chemical Bond

Ionic Bond

Covalent Bond

Single Covalent Bond

Double Covalent Bond

Triple Covalent Bond

Coordinate Covalent Bond

Polar and Nonpolar covalent bond

Metallic Bond

Introduction:

The term chemical bond can be defined as the force of attraction between holding atoms. In other words, during bond formation there is a certain energy holding atoms together.

Octet rule is the attaining of eight electrons in the valence shell of an atom either by sharing, losing or gaining of electrons and this completion of octet rule is important for attaining stability.

If the bond formation takes place between different kinds of ions then this is because of electrostatic energy but if the bond formation takes place between same kinds of atoms or those atoms having comparable electronegativities then this is because of sharing of electrons between those atoms.

Types of Chemical Bond:

The term bonding electrons can be defined as the valence electrons or outermost electrons of an atom that are involved in the formation of a chemical bond.

Different types of chemical bonds are formed on the basis of how their outermost electrons are involved in the formation of a chemical bond such as ionic bond, covalent bond, coordinate covalent bond and metallic bond.

Ionic Bond:

When alkali and alkaline earth metals react with the elements of group sixteen or seventeen which are non-metals having the tendency to gain electrons, they form an ionic bond.

Alkali and alkaline earth metals of group one and group two are highly electropositive elements and have the tendency to lose electrons easily forming positive ions that are cations.

While on the other hand, non-metals of group sixteen and seventeen are highly electronegative elements and have the tendency to gain electrons easily forming negative ions that are anions.

Hence the bond which is formed between metals and nonmetals that is by the complete transfer of electrons from one atom to another atom is known as ionic bond.

The compound which is formed as a result of ionic bond is known as ionic compound and during the formation of ionic bond heat is usually given out so these can also be said as exothermic.

Some of the examples of ionic bonds include the formation of lithium fluoride, lithium chloride, lithium bromide, lithium iodide, sodium fluoride, sodium chloride, sodium bromide and sodium iodide etc.

As all the examples given above are of ionic bonds so all these are ionic compounds.

Covalent Bond:

When the elements of group thirteen to seventeen that are nonmetals react with each other they form a chemical bond by the mutual sharing of electrons between them known as covalent bond.

In simple words we can say that a covalent bond is formed between nonmetals by the mutual sharing of electrons and those compounds which are formed as a result of covalent bond between their atoms are known as covalent compounds.

Covalent bond is further divided into single, double and triple covalent bond depending upon the number of valence electrons shared by the bond forming atoms.

Single Covalent Bond:

Single covalent bond is formed between two atoms when they share only a single valence electron between them, that is one electron by one atom and one electron by the other atom.

In a single covalent bond, only one bond pair is formed between two atoms which is represented by a single line between those two bond forming atoms.

Examples of single covalent bonds include formation of hydrogen molecule, chlorine molecule, hydrochloric acid and methane etc.

Single covalent bond between hydrogen molecule and chlorine molecule is usually represented as H-H and Cl-Cl respectively.

Double Covalent Bond:

Double covalent bond is formed between two atoms when they share two valence electrons between them, that is two electrons by one atom and similarly two electrons by the other atom.

In a double covalent bond, two bond pairs are formed between two atoms which are represented by a double line between those two bond forming atoms.

Examples of double covalent bonds include formation of an oxygen molecule and ethene molecule.

Triple Covalent Bond:

Triple covalent bond is formed between two atoms when they share three valence electrons between them, that is three electrons by one atom and similarly three electrons by the other atom.

In a triple covalent bond, three bond pairs are formed between two atoms which is represented by three lines between those two bond forming atoms.

Examples of triple covalent bonds include formation of nitrogen molecule and ethyne molecule.

Coordinate Covalent Bond:

Formation of a covalent bond in which a bond pair of electrons is donated by one atom to another atom is known as a coordinate covalent bond.

The term donor is usually given to that atom which donates a pair of electrons to another atom and the atom which accepts a pair of electrons is known as acceptor.

The coordinate covalent bond is usually represented by a small arrow of which head is towards the acceptor atom.

Lone pair is the pair of electrons which is non-bonded like the one present on the nitrogen in ammonia.

Coordinate covalent bond is formed when the lone pair present on nitrogen in ammonia is donated to a hydrogen ion which is a proton.

Examples of coordinate covalent bond include formation of ammonium radical and formation of boron trifluoride.

Polar and Nonpolar covalent bond:

When the covalent bond is formed between two same types of atoms that is homo-atoms then the bond is known as non-polar covalent bond in which the attraction for the bonded electrons between the two bonded atoms is equal from both sides of atoms and hence the bonded electron pair is equally shared among the two bonded atoms such as formation of hydrogen molecule and chlorine molecule.

On the other hand if the covalent bond is formed between two different kinds of atoms that is hetero-atoms then the bond is known as polar covalent bond.

In this case the bonded electron pair is not equally shared among the two bonded atoms because the atoms forming bonds are different, having different values of electronegativity.

The atom which is more electronegative pulls the bonded pair of electrons towards itself and a partial negative charge develops on it while a partial positive charge develops on other atom having less electronegativity.

As partial positive charge is developed on one atom and partial negative charge is developed on the other atom hence polarity is created in the bond and is known as polar covalent bond.

Examples of polar covalent bonds include the formation of hydrochloric acid, water and hydrogen fluoride.

Those compounds which are formed as a result of polar covalent bonds are known as polar compounds and those resulting from non-polar covalent bonds are known as non-polar compounds.

Metallic Bond:

Metallic bond is formed by the mobile or free electrons of metals. In metallic bonds, metals make bonds with each other. Atoms of metals are holded by these mobile electrons. Different characteristics of metals include high melting and boiling points, good conductors of heat and electricity, hard and heavy nature etc.