Formation of Covalent Bond within Hydrogen Chloride Molecule

When the chlorine atom is sufficiently close to the hydrogen atom, a simple covalent bond is formed with two electrons. Since the chlorine atom has a higher electronegativity than the hydrogen atom, the two shared electron are partially attracted to the chlorine atom. There is a partially negative charge on the chlorine atom and a partially positive charge on the hydrogen atom. This type of covalent bond is called a polar bond.