It should be noted that there are certain characteristics of the covalent bond and that differentiates them from other chemical processes that occur at the molecular level, and that is that these are only carried out between non-metallic elements; Covalent bonds also include single, double, or triple bonds, in which 2, 4, or 6 electrons are shared, respectively.
Similarly, molecules created from covalent bonds can be separated by applying less energy than the ionic components. Also, when the two atoms have equal electronegativity, the covalent bond will be stronger. These types of bonds are common in living beings and in the composition of their molecules.
On the other hand, there are two types of covalent bonds that, depending on the affinity of the electrons that each atom possesses, are classified as polar and non-polar.
What is a Polar Covalent Bond?
The polar covalent bond is given by the union of two atoms of different elements, and it never occurs between atoms of the same element, whose electron difference is greater than 0.4 and less than 1.7.
The atoms with polar covalent bond in their interaction, keep the electrons closest to the atom with the highest electronegative charge in the nucleus, which translates into polarity, and which in turn, generate molecules that in their electronic cloud will present areas with a density greater number of negative charges than others with positive ones, which are known as dipoles.
What in a Nonpolar Covalent Bond?
A nonpolar covalent bond occurs when two atoms of the same element come together to form a molecule that contains an electronegativity with a range from 0.4 to 0, which is why it is considered very low or non-existent, since there are no electrons to be found. the ends of the molecule, therefore there is no polarity.
Similarly, a nonpolar covalent bond can occur between two different elements, as long as they have a minimal difference in electronegativity in their charge.
The behavior of the electrons generates a molecule with a uniform electronic cloud, and the intensity with which the electrons are attracted to the nucleus is the same in both atoms.
Difference Between Polar and Non-Polar Covalent Bond
- The polar covalent bond occurs only between different elements, while the non-polar covalent bond can be found between different elements or in the union of atoms of the same element.
- The electronegativity range of the nonpolar covalent bond may be absent or very low, between 0 and 0.4; while in the polar covalent bond, the electronegativity index varies from 0.4 to 1.7.
- The electrons in the polar covalent bond are located at the ends of the atoms as they are attracted by the nucleus with a higher electronegative charge; On the contrary, in the nonpolar covalent bond, the electrons stay close to their own nucleus.
- Nonpolar covalent bonds generate a molecule with a uniform electron cloud, due to the behavior of the electrons. On the other hand, in polar covalent bonds, it will have the same electron cloud, but it will have a higher density towards the negative pole than where the charge is positive.