The two main varieties of chemical bonds include the ionic bond and the covalent bond. The third variety named as co-ordinate bond has properties that are intermediate to that of ionic bond and the covalent bond. If the bond is formed between the metal ions, it is termed as metallic bond.
Let us see each of these bonds in detail.
Ionic bond: an ionic bond is formed by complete transfer of electrons from an atom having more number of electrons than the required octet configuration in the outer shell to an atom that is deficient in electrons in the outer shell. In technical terms, ionic bond can be said as a bond between electron donating electronegative elements and the electron accepting electropositive elements.
A very good example for a compound with ionic bond is the common salt which is sodium chloride. In this case sodium acts as an electronegative atom with one extra electron and chlorine acts as an electron acceptor with one less electron. These two atoms with opposite charges attract strongly resulting in the formation of ionic bond. After the bond formation, both the atoms have the octet configuration and the compound remains stable.
Compounds with ionic bond are crystalline in nature. Due to flow of electrons they act as conductors of electricity in molten state. These compounds have high melting and boiling point.
Covalent bond: unlike ionic bond, covalent bond is formed as a result of sharing of electrons between two elements that are deficient in electrons. Both the atoms involved in the bond formation are electronegative in nature. Carbon is a very good example of an element that mainly forms covalent bond.
Here is an example for the formation of oxygen molecule. Here one oxygen atom pairs with the other oxygen atom. Both have four unshared electrons and four shared electrons. Two bonds are formed between them....