Chemical Bonding defination | Types -Chemfun

   Chemical Bonding

“A chemical bond is a force, that holds together two or more two atoms, ions, and molecules which results in a large variety of compounds, and this process is called chemical bonding”. This force is also responsible for the shape of molecules of that compounds.

Why does an atom make bond ? 

Here’s the biggest query, why do atom react? And the simplest and easiest answer to understand is that it’s a universal rule that everybody or everything wants to be stable. And in that everything ATOM is also present. So atoms also want to be stable. Atom is stable if its valence shell is filled. The valence shell means the outermost shell of that atom. The shell contains electrons. 

• It’s been observed that chemical reactivities of elements depend upon their electronic configuration.

How does an atom get stable?

All atoms get their stabilization by losing or gaining or sharing the outermost electrons to attain the nearest noble gas configuration. The tendency of an atom to attain eight electrons in its valence shell is called “Octet Rule”.

Example of chemical bonding:

Let’s take example chlorine has 7 electrons in its outermost shell. It gets stable and makes bonds with other atoms of another element by gaining 1 electron from it.

               2H + Cl2———> 2HCl 

In this above reaction two moles of hydrogen react with chlorine gas in that way, single H has 1 electron in its outermost shell, on the other hand, Cl has 7 Electrons in its outermost shell, so H losses its 1 electron to Chlorine and make a stable compound HCL. 

Why just valence electrons are responsible for bonding?

Electrons revolve around the nucleus in shells. The shell which is nearest to the nucleus must have more force of attraction because the nucleus is positively charged and electrons are negatively charged. And the valence shell has the least attraction with that nucleus. And those inner shell electrons are tightly bonded to outermost shell electrons. So that's why the loss or gain of an electron from a valence shell is easy. That's why valence shell electrons are just responsible for chemical bonding.

Types of Chemical Bonding:

There are several types of chemical bonding depending upon the type of molecule and, sometimes structure of 

a molecule. Following are some important types : 

• Ionic Bond.
• Covalent Bond.
• Coordinates covalent Bond.
• Metallic Bond.
• Hydrogen Bond.

Ionic bond: 

“The type of chemical Bond which is formed by the complete transfer of electrons from one atom to another atom is called Ionic Bond”.

• The elements of Group-1 and Group-2 being Metals tend to lose their outermost electrons and Group-15 to Group-17 being Non-metals tend to gain electrons. That's why metal reacts with non-metals, thus such type of a bond between metal and non-metals is called an Ionic Bond.

Example of Ionic bond :

The perfect example of an Ionic bond is the formation of NaCl. 

2Na + Cl2 ———> 2NaCl.

Electronic Configurations: 

The electronic configuration of sodium and chlorine shows that Sodium has one electron in its valence shell while chlorine has 7 electrons. Chlorine needs 1 electron,

Sodium gives its 1 valence electron to the chlorine and makes a bond. This bond is between the metal(Na) and non-metal(Cl), which is ionic bond.

Covalent bond : 

“The type of a bond, which is formed by the mutual sharing of electrons from one atom to another(maybe the same atom), is called a covalent Bond”.

Types of covalent Bond: 

Covalent bonds have three types: 

• Single Covalent Bond.
• Double Covalent Bond.
• Triple covalent Bond. 

By category there are two types : 

• Polar covalent Bonds.
• Non-polar covalent Bonds.

Examples of Covalent Bond : 

H2O(water) and CO2(carbon dioxide) are the most common examples of covalent Bond.

Co-ordinates covalent Bond :

“The type of bond in which Bond pair of electrons is donated by one atom to another one is called Co-ordinates covalent or dative covalent bond”.

Example of Co-ordinates Covalent Bond:

The bond between the NH3 and BF3 is co-ordinates covalent Bond, Nitrogen has a lone pair and it tends to donate it so that's why it donates its lone pair to Boron which tends to accept this lone pair. Here’s NH3 is Donar while BF3 is the acceptor. This bond has shown by the red arrow in the picture below.

Metallic Bond : 

“The bond which is formed between the metal atoms due to the free and mobile electrons is called Metallic Bond”. 

Examples of metallic bonds: 

Gold, silver, and copper are some best examples of metallic Bonds. These are also good conductors of electricity.