Write a note on the Covalent bond?
ANSWER:
- COVALENT BOND:
INTRODUCTION:
G.N Lewis proposed that atoms could attain stable electronic configuration by sharing electrons between them.
Covalent Bond Definition:
The bond which is formed by the mutual sharing of electrons is called a covalent bond.
REPRESENTATION OF COVALENT BOND:
The shared pair of electrons are represented by a dash between the two bonded atoms.
CONDITIONS FOR COVALENT BONDING:
- Both the elements should be non- metals
- The electronegativity difference between two bonded atoms should be less than 1.7
EXAMPLE:
- Hydrogen molecule (H2)
- Oxygen molecule (O2)
- Hydrochloric acid (HCl)
- Hydrogen bromide (HBr)
Types Of Covalent Bond:
The covalent bond is further divided into three types:
- Single covalent bond
- Double covalent bond
- Triple covalent bond
Single Covalent Bond:
Definition:
“The bond in which the two atoms share one electron each to form a pair of electrons is called the single covalent bond.”
SINGLE BOND REPRESENTATION:
A single straight line (-) shows the single covalent bond.
EXAMPLES OF SINGLE BONDS:
H2
Cl2
F2
Example of Cl2:
- A chlorine molecule is formed from two chlorine atoms.
- The chlorine atom’s electronic configuration is (2,8,7).
- A chlorine atom has 7 electrons in its valence shell.
- The two chlorine atoms mutually share one electron to form a chlorine molecule (Cl2).
- Therefore, both chlorine atoms attain the electronic configuration of (Ar) and complete their octet.
Example of CH4:
- Carbon has four electrons in its outermost shell and needs more 4 electrons to attain the noble gas (Ne) configuration
- Therefore, four atoms of hydrogen mutually share one electron each with a carbon atom to form a molecule of methane (CH4)
Double Covalent Bond:
Definition:
“The bond in which two atoms share two electrons each to form two pairs of electrons is called a double covalent bond.
Double bond Representation:
A double straight line(=) shows a double covalent bond
Examples of Double bonds:
O2
C2H4
CO2
Example of Oxygen (O2):
- An oxygen molecule is formed from two oxygen atoms
- The oxygen atom electronic configuration is (2,6)
- An oxygen atom has six electrons in its valence shell and it shares two electrons with another oxygen atom to form an oxygen molecule (O2)
- In this way, both oxygen atoms attain inert gas neon (Ne) electronic configuration and complete their octet.
O + O –> O2
Example of Carbon Dioxide
Similarly in carbon dioxide, the carbon atom shares four electrons with two oxygen atoms and forms two double covalent bonds.
O + C + O –> CO2
Triple Covalent Bond
Definition:
The bond in which two atoms share three electrons each, to form three pairs of an electron is called a triple covalent bond.
Triple bond Representation
It is represented by triple straight lines
Example of Triple Bond:
- N2 ( Nitrogen molecule)
Examples of Nitrogen (N2)
The nitrogen molecule is formed from two nitrogen atoms.
The nitrogen atom’s electronic configuration is (2,5)
A nitrogen atom has five electrons in its valance shell and it shares three electrons with another nitrogen atom to form a nitrogen molecule.
In this way, both nitrogen atoms attain the nearest inert gas electronic configuration and complete their octet.
N + N –> N2
Also Watch !!!
Covalent bonds Definition Examples and Types( Urdu /Hindi)
This video will help you in understanding the concept of Covalent bonds with the help of the easiest definition, examples of covalent bonds and also the types of covalent bonds. You will be able to understand the types of covalent bonds on the basis of electron pair sharing, Single Covalent Bond Double Covalent Bond Triple Covalent Bond along with definitions and examples. Also discuss the types of covalent bonds on the basis of electronegativity difference, which is a polar covalent bond and non-polar covalent bonds with definition and examples.
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