What is the fission of a covalent bond? Explain its types with examples and the main differences.

(N/A) The fission of a covalent bond refers to the process of breaking a covalent bond. $A$ covalent bond can be cleaved in two ways:
$(i)$ Heterolytic cleavage
$(ii)$ Homolytic cleavage
| Feature | Heterolytic Cleavage | Homolytic Cleavage |
| :--- | :--- | :--- |
| $(i)$ Example | $H_3C-Br \rightarrow H_3C^+ + Br^-$ (forms positive and negative ions) | $H_3C-Br \rightarrow H_3C\cdot + \cdot Br$ (forms free radicals) |
| $(ii)$ Reaction Type | Ionic or polar reactions (nucleophilic or electrophilic) | Free radical or nonpolar reactions |
| $(iii)$ Mechanism | The shared pair of electrons remains with one of the fragments | One electron of the shared pair goes to each of the bonded atoms |
| $(iv)$ Intermediate | Forms carbocations or carbanions | Forms free radicals |