In a molecule formed by covalent bonding, what happens between the atoms?

In a molecule formed by covalent bonding, the fundamental mechanism involves the sharing of electrons between atoms. This sharing allows each atom to attain a more stable electron configuration, similar to that of noble gases, which is known as the octet rule for many elements.

When two nonmetals bond covalently, they each contribute one or more of their valence electrons to form a bond. This results in a mutual attraction between the positively charged nuclei of both atoms and the shared electrons, effectively holding the atoms together in a stable molecule. The degree to which the electrons are shared can vary depending on the electronegativities of the involved atoms, which can sometimes lead to unequal sharing, but the defining characteristic of covalent bonding is the presence of shared electrons.

This process contrasts with other types of atomic interactions; for instance, in ionic bonding, electrons are transferred from one atom to another, resulting in charged ions instead of shared electrons. Therefore, the correct understanding of covalent bonding centers on the sharing of electrons, forming a cohesive unit where the atoms are bound together rather than repelling or remaining entirely uninvolved with one another.