What type of bonding involves the sharing of electron pairs between atoms?

Covalent bonding is characterized by the sharing of electron pairs between atoms. This type of bonding typically occurs between nonmetals, where two atoms share one or more pairs of valence electrons to achieve stability, often leading to the formation of molecules. The shared electrons allow each atom to attain the electron configuration of a noble gas, fulfilling the octet rule for many elements.

In contrast, metallic bonding involves a 'sea of electrons' that are free to move around, which helps explain the conductivity and malleability of metals. Ionic bonding, on the other hand, occurs when electrons are transferred from one atom to another, resulting in the formation of charged ions that attract each other due to electrostatic forces. Hydrogen bonding involves weak interactions between a hydrogen atom covalently bonded to a highly electronegative atom and another electronegative atom, which does not involve sharing of electron pairs between atoms in the same way as covalent bonding.

Thus, the defining feature of covalent bonding is the actual sharing of electron pairs, making it a distinct and essential type of chemical bonding in molecular compounds.