Saturday, February 29, 2020

Covalent bond-definition-examples-formation energy and types


Covalent bond definition in chemistry



When a chemical  bond is formed  between two similar or different atoms by sharing of one or more electrons pairs by them to gain the more stable nearest inert gas electronic configuration , then the bond is called covalent bond . It is also called molecular bond.



Covalent bond-


In the formation of covalent  bond, the atoms  form the electron-pair in such a way , so that a stable balance of attractive and repulsive forces acts among the concern atoms.


What is covalency in chemistry ?



When two or more atoms in their ground state or excited state , [ to attain the more stable nearest inert gas electronic configuration ], by sharing of their outer most 

valence electrons forms one or more electron pair, through which they gain a power for chemically attachment, then this power of attachment is called covalency.
  

Covalent bond examples



There are a large number of covalent compounds  as well as covalent bond  in the world .

Covalent bond examples


For example , covalent  molecule of elements and covalent molecules of compounds .  
A few examples of both types of covalent  bonded molecules and their formation are shown here.


Covalent bond examples

Covalent bond examples



Covalent bond formation energy 



Any covalent bond is formed by sharing of two opposite  spinning electrons.

Due to formation of electron pair with this two opposite  spinning electrons, a electro-magnetic force  of attraction is appeared, this is called covalent bond  formation energy.
  

Types of covalent bond with definition and examples 




There are three types of covalent bond in chemistry . 

                                                       ( I ) covalent single bond
                                                       ( II ) covalent double bond  and
                                                       ( III ) covalent triple bond .

 

( I ) covalent single bond 


If one electron-pair is equally shared between two similar or different atoms , then the resulting bond formed is called covalent single bond.

The bond is expressed by single dash . For example ,  Cl – Cl .
Formation of covalent single bond by sharing of electron is shown below.



covalent single bond



( II ) covalent double bond 


 If two electron-pair is equally shared between two similar or different atoms , then the resulting bond formed is called covalent double bond

The bond is expressed by double dash. For example, O = O.
Formation of covalent double bond by sharing of electron is shown below.


covalent double bond  :

( III ) covalent triple bond 


If three electron-pair is equally shared between twoatoms, then the resulting bond formed is called covalent triple bond . 

The bond is expressed by triple dash.For example , nitrogen ( N2 ).
Formation of covalent triple bond by sharing of electron is shown below.


covalent triple bond :


Condition for the formation of covalent bond as well as chemical compounds .




Generally, a covalent  bond is formed by sharing of electrons between two non-metallic atoms.


The number of valence electrons of participating two atoms in covalent bonding must 
be 4,5,6 and 7 ,so that each atom can complete their octet by sharing of electrons and gain more stable inert gas electronic configuration.


The ionization energy of the participating atoms in covalent bonding should be high .

The two participating atoms in covalent  bonding should have high as well as equal  electron affinity.



Condition for the formation of covalent bond as well as chemical compounds .



The electronegativity of the participating atoms in covalent bonding should be equal  or about equal. That is, their electronegativity difference must be sufficiently low.

With increasing the nuclear charge on the participating atom in covalent bonding, the tendency for the formation of covalent bond increases.




Summary



  • Covalent bond definition in chemistry.
  • Covalent bond definition in chemistry.
  • Covalent bond examples in chemistry .
  • Covalent bond formation energy .
  • Types of covalent bond with definition and examples.
  • Condition for the formation of covalent bond as well as chemical compounds.












No comments:

Post a Comment