Question

Give reasons for the following : 

Molecules of hydrogen and chlorine have single covalent bonds between their atoms while oxygen has a double covalent and nitrogen a triple covalent bond respectively. 

Answer 1

Hydrogen – Each of the two H atoms contributes one electron so as to have one shared pair of electrons between them.Both atoms attain stable – duplet structure, resulting in the – formation of a -single covalent bond [H-H] between them.

Chlorine – Each of the two Cl atoms contributes one electron so as to have one shared pair of electrons between them. Both atoms attain stable – octet structure, resulting in the – formation of a – single covalent bond [Cl – Cl] between them.

Oxygen – Each of the two O atoms contributes two electron so as to have two shared pair of electrons between them. Both atoms attain stable – octet structure, resulting in the – formation of a – double covalent bond [O = O] between them.

Nitrogen-  Each of the two N atoms contributes three electron so as to have three shared pair of electrons between them. Both atoms attain stable – octet structure, resulting in the – formation of a – tripple covalent bond [N = N] between them.