When does covalent bonding occur?

Question

Wyatt Atkins · Accepted Answer

Covalent bonding occurs when atoms share electrons. By sharing their outermost (valence) electrons, atoms can fill up their outer electron shells and gain stability by getting an octet of electrons. Nonmetals readily form covalent bonds with other nonmetals.

Only when two atoms of the same element form a covalent bond are the shared electrons actually shared equally (e.g., #Cl_2#). When atoms of different elements share electrons, the electrons are drawn more toward the atom with the higher electronegativity, as in HCl. The result is a polar covalent bond.

If the electronegativity difference between the two elements is very small (0.4 or less), the electrons are shared almost equally, and the bond is considered to be nonpolar covalent. If the electronegativity difference is between 0.4 and 1.7, the bond is polar covalent. If the electronegativity difference between the two elements is large (1.7 or greater), the bond is considered to be ionic.

Jose Ayala · Answer

undefined Covalent bonding occurs when atoms share one or more pairs of electrons in order to achieve a more stable electron configuration. This type of bonding typically occurs between nonmetal atoms, where each atom contributes electrons to the bond. Covalent bonds are characterized by the sharing of electrons between atoms, resulting in the formation of molecules.