A covalent bond is a type of chemical bond that occurs when two atoms share one or more pairs of electrons. This sharing allows each atom to attain the electron configuration of a noble gas, leading to greater stability.
Covalent bonds typically form between nonmetal atoms, which have similar electronegativities. Since both atoms in a covalent bond have a strong tendency to attract electrons, they effectively pull the shared electrons closer to themselves, which results in a bond that is generally stronger than other types of bonds, such as ionic bonds.
Examples of substances that form covalent bonds include diatomic molecules like oxygen (O2) and nitrogen (N2), as well as compounds such as water (H2O), carbon dioxide (CO2), and organic compounds like methane (CH4). These molecules exhibit distinct physical and chemical properties due to their covalent bonding, like low melting and boiling points compared to ionic compounds.