Explanation:
Covalent bonds are the bonds that occur due to sharing of electrons between two atoms.
For example, H atom has 1 electron in its valence shell and Cl atom has 7 electrons in its valence shell. Therefore, both of them will share an electron with each other and thus, it will result in the formation of a covalent bond.
Whereas when a metal and non-metal combine together the it will result in the formation of an ionic bond because transfer of electrons will take place.
On the other hand, when metal combines with metal then it results in the formation of metallic bonding.
Thus, we can conclude that the following pairs would form covalent bonds.
