Which type of bond involves sharing a pair of electrons between atoms in a molecule?

A covalent bond is characterized by the sharing of a pair of electrons between atoms in a molecule. This type of bond typically occurs between non-metal atoms, which have similar electronegativities and thus the propensity to attract electrons equally. When two atoms form a covalent bond, they accomplish this by allowing their outer electron shells to overlap, enabling each atom to attain a more stable electronic configuration resembling that of noble gases, usually leading to a full valence shell.

The nature of covalent bonding allows for the formation of discrete molecules. For example, in a water molecule (H2O), each hydrogen atom shares one electron with the oxygen atom, resulting in two covalent bonds. This concept is fundamental in understanding molecular structures and chemical reactions.

In contrast, other types of bonds play different roles; ionic bonds involve the transfer of electrons from one atom to another rather than sharing, while metallic bonds feature a 'sea of electrons' that are shared among many atoms in a metallic structure. Network bonds form extensive lattice structures, leading to strong but less discrete materials. Thus, the correct identification of covalent bonds is essential for understanding the behavior of many molecular compounds.