Unit 6

Introduction to polar and non-polar covalent bonding

Even though we say sharing occurs in covalent bonding, the sharing is not always 50-50. Sharing would only be equal in identical atoms such as H-H or 0=0.

When identical atoms are sharing electrons, sometimes there will be a temporary dipole-dipole attraction in the non-polar bond( The electronegativity of atoms is the same).
Example of a temporary dipole-dipole attraction: H-H

However, when an atom in a covalent bond is more electronegative than the other atom, permanent dipole-dipole attraction occurs such that the electrons will be "pulled" towards the atom that is more electronegative than the other.

Example of a permanent dipole-dipole attraction : H-Cl
Since Cl is a Group 7 atom, it will be highly electronegative, "pulling" the electrons to its side such that it will be more negative on the side of the atom Cl and more positive on the side of atom H.
This results in an unequal distribution of charge on the whole molecule.

Video summary on polar and non-polar covalent bonding and provides an insight into the next topic, hydrogen bonding