What is a covalent bond?

A covalent bond is defined as a bond that involves the sharing of electrons between atoms. This occurs primarily between nonmetals, where two atoms come together to achieve a more stable electron configuration. By sharing one or more pairs of electrons, each atom can fill its outer electron shell, which is often necessary for stability according to the octet rule.

The sharing of electrons can lead to the formation of single, double, or even triple bonds, depending on how many pairs of electrons are shared. This type of bonding results in the formation of molecules, which can have distinct physical and chemical properties compared to the individual atoms.

The other options do not accurately describe covalent bonds: the transfer of electrons characterizes ionic bonds, while the mention of strong forces holding nuclei together refers to nuclear forces. Thus, the definition of a covalent bond revolves around the concept of electron sharing, making it a fundamental aspect of how nonmetal atoms interact to form stable compounds.