Calculate the difference between their electronegativity values. Only the absolute difference is important. I. Nonpolar Covalent: This type of bond occurs when there is equal sharing (between the two atoms) of the electrons in the bond. Molecules such as Cl2, H2 and F2 are the usual examples.

Electronegativity is the strength an atom has to attract a bonding pair of electrons to itself. When a chlorine atom covalently bonds to another chlorine atom, the shared electron pair is shared equally. The electron density that comprises the covalent bond is located halfway between the two atoms.

(Pure covalent bonds result when two atoms of the same electronegativity bond.) Intermediate differences in electronegativity between covalently bonded atoms lead to polarity in the bond. As a rule, an electronegativity difference of 2 or more on the Pauling scale between atoms leads to the formation of an ionic bond.

To determine the polarity of a covalent bond using numerical means, find the difference between the electronegativity of the atoms; if the result is between 0.4 and 1.7, then, generally, the bond is polar covalent.