Which type of bonds are formed when non-metal atoms share a pair of electrons?

When non-metal atoms share a pair of electrons, they form covalent bonds. This type of bond occurs due to the mutual attraction that arises from the sharing of electrons between the atoms, allowing each atom to attain a stable electron configuration, typically resembling that of the nearest noble gas. Covalent bonding is characterized by the strong interactions between the atoms that share electrons, enabling the formation of molecules with distinct chemical properties.

In contrast, ionic bonds involve the transfer of electrons from one atom to another, leading to the formation of charged ions that are held together by electrostatic forces. Metallic bonds, on the other hand, arise from the attraction between metal atoms and a 'sea' of delocalized electrons, which is different from the sharing mechanism seen in covalent bonds. Lastly, hydrogen bonds are a weak type of interaction that occurs between molecules when hydrogen is covalently bonded to highly electronegative atoms like oxygen or nitrogen, rather than involving the sharing of electrons in a fixed pair between two non-metals. Thus, the formation of covalent bonds is uniquely defined by the sharing of electron pairs between non-metal atoms.