The electronegativity difference between hydrogen (2.20) and chlorine (3.55) is 1.35. This difference indicates a polar covalent bond will form between them.

Here's why:

* Covalent bond: Electrons are shared between the atoms, but not equally.

* Polar covalent bond: One atom attracts the shared electrons more strongly than the other, creating a partial positive charge (δ+) on the less electronegative atom and a partial negative charge (δ-) on the more electronegative atom.

In the case of HCl, chlorine is much more electronegative than hydrogen. This means the shared electrons spend more time near the chlorine atom, making it slightly negative (δ-) and the hydrogen atom slightly positive (δ+).