How do you distinguish between polar and nonpolar covalent bonds?

Question

Elias Aguila · Accepted Answer

All covalent bonds between different atoms are polar to some extent, it's just that the properties associated with polar bonds are generally observed in the most polar ones.

Polarity is caused by a difference in electronegativity between the two atoms that are bonded. In reality, unless the two atoms are identical (e.g. #H_2# or #O_2#) there will always be a certain amount of polarity there, but for the really extreme cases you need to consider very large differences in electronegativity, for example, bonds between oxygen and hydrogen, or between oxygen and carbon. The more electronegative an atom is, the more it draws the electron charge density towards itself, partially charging itself with a negative charge (while partially charging the other atom with a positive charge).

Emilia Alvarez · Answer

undefined Polar covalent bonds occur when atoms with different electronegativities share electrons unequally, resulting in a partial positive and partial negative charge. Nonpolar covalent bonds occur when atoms with similar electronegativities share electrons equally, resulting in no net dipole moment.