What is the Difference Between Covalent and Polar Covalent?

The main difference between covalent and polar covalent bonds lies in the sharing of electrons and the electronegativity of the atoms involved. Here are the key differences:

1. Electron sharing: In covalent bonds, electrons are shared between atoms and are attracted by the nuclei of both atoms. In pure covalent bonds, the electrons are shared equally, while in polar covalent bonds, the electrons are shared unequally, as one atom exerts a stronger force of attraction on the electrons than the other.
2. Electronegativity: The ability of an atom to attract a pair of electrons in a chemical bond is called its electronegativity. The difference in electronegativity between two atoms determines how polar a bond will be. In a diatomic molecule with two identical atoms, there is no difference in electronegativity, so the bond is nonpolar or pure covalent. When the electronegativity difference is very large, as is the case between metals and nonmetals, the bonding is characterized as ionic.
3. Bond polarity: In a nonpolar covalent bond, the electrons are shared equally between the two atoms, resulting in no net dipole moment. In a polar covalent bond, the electrons are unequally shared, leading to a net dipole moment, which results in the bond having a specific dipole direction.
4. Examples: Nonpolar covalent bonds are found in homonuclear diatomic molecules, such as H-H, O-O, and N-N. Polar covalent bonds are found in molecules like H-Cl, H-F, and N-H, where the electronegativity difference between the atoms is significant enough to create an unequal sharing of electrons.

In summary, nonpolar covalent bonds result from equal sharing of electrons between atoms with similar electronegativities, while polar covalent bonds result from unequal sharing of electrons between atoms with different electronegativities. The polarity of a bond can be estimated by calculating the absolute value of the difference in electronegativity between the atoms involved.

Comparative Table: Covalent vs Polar Covalent

The main difference between covalent and polar covalent bonds lies in the sharing of electrons between the atoms involved. Here is a table summarizing the differences between covalent and polar covalent bonds:

In a covalent bond, electrons are shared equally between the bonded atoms, resulting in a nonpolar bond. In contrast, a polar covalent bond occurs when electrons are unequally shared between atoms with different electronegativities, leading to a polar bond.