Ans : Ionic Bond OR Electrovalent Bond :
The attraction that binds oppositely charged ions together is termed as electrovalent bond or ionic bond. It is formed between the atoms with electronegativity difference of more than 1.7.
Formation Of Ionic Bond:
In this type of bond there is complete transfer of electrons from one atom to another. The atom that transfers electrons gets positive charge & the atom that gains electrons gets negative charge. The strong electrostatic force acting between positive & negative ions holds them together.
Covalent Bond :
A chemical bond which is formed by the mutual sharing of electrons between the atoms is termed as Covalent Bond.
Formation Of Covalent Bond:
When atoms of similar electronegativities react , the transfer of electrons does not occur. In such case atoms achieve inert gas configuration by completing their outer most shell by means of sharing of unpaired electrons & thus a covalent bond is formed.