Step-by-step explanation:
Polarity in a molecule arises due to unequal sharing of electrons. Hydrogen atom has one electron whereas chlorine atom has 17 electrons.
Thus, in order to complete their octet both H and Cl will share an electron with each other.
It is also known that chlorine is much more electronegative than hydrogen. Therefore, it will readily attract one electron from hydrogen atom.
Hence, we can conclude that the polarity of the HCl molecule is due to the following.
- greater attraction of the chlorine nucleus for the shared electrons.
- large differences in electronegativity.