Answer : The diatomic molecule of chlorine, Cl₂, is held together by a SINGLE covalent bond.
Covalent Bond :
It is type of chemical bond, which is formed by sharing of electron between atoms . The covalent bond is formed between two non metals . The valance electron are shared to form the bond . The shared electrons are known as BONDING electron pair and the electron pair which do not take part in bonding are known as NON- BONDING electron pair. Example : O₂ , H₂ , H₂O, NH₃ etc .
Formation of covalent bond in Cl₂ :
Chlorine is present in group 17 in p block , It is a non metal .
The electronic configuration of Cl is : 1s² 2s² 2p⁶ 3s² 3p⁵ .
Since the outer shell is n= 3 , which has 7 electrons in it , hence Cl has 7 valence electrons in it .
From electronic configuration , it can be seen that Cl need 1 electron to complete its octet (3s² 3p⁶ ). Hence when two Cl atoms come close they share one-one electron with each other (as shown in image ) .
Now the octet of both the atom are complete and they are in stable state together .
When both Cl atom share one e⁻ , there is a bond formed between Cl atoms . One bond consists of 2⁻ . Hence in Cl₂ SINGLE covalent bond present .
Cl + Cl -> Cl₂
