(a) What type of chemical bond is present in chlorine molecule? Explain your answer.
(b) Explain the formation of a chlorine molecule on the basis of electron theory of valency.

(a) Covalent bond is present in a chlorine molecule as two atoms of the same element combine to form the molecule.

(b) Chlorine is an electronegative atom. Its atomic number is 17(2,8,8,7). It completes its octet by adding one electron to its outer shell and becomes stable. It acquires this electron by sharing with another chlorine atom and form a chlorine molecule. A strong covalent bond is formed between the two chlorine atoms. Therefore, the electronic configuration of chlorine becomes 2,8,8.