Define a covalent bond.

A covalent bond is defined as the bond formed when two atoms share one or more pairs of electrons. This sharing allows each atom to achieve a more stable electronic configuration, often resembling that of noble gases. In molecules, this bond creates a strong interaction between the bonded atoms, which is essential for the formation of organic compounds and many other substances.

In covalent bonding, the shared electrons allow each atom to effectively 'own' a portion of the shared pair, leading to a stable balance. This bond can involve single, double, or triple pairs of shared electrons, depending on the number of pairs involved.

Other definitions do not capture the essence of covalent bonds. For instance, the idea of transferring electrons to create ions pertains to ionic bonding, and the attraction between positively charged ions does not reflect the electron-sharing characteristic of covalent bonds. Additionally, forming bonds between a metal and a non-metal typically results in ionic bonding, not covalent, which further reinforces the distinct nature of covalent bonds among types of chemical bonding.