Polar bond in hydrogen chloride molecule. Image 3 of 3 illustrating the sharing of electrons (dots and crosses) between a hydrogen atom (H) and a chlorine atom (Cl) to form a molecule of hydrogen chloride (HCl). This third image in the sequence shows the effect of electronegativity. Chlorine exerts more of a pull on the electron pair than the hydrogen atom. This causes the covalent bond to become polarised, creating a dipole moment. There is a partial negative charge (delta minus) at the chlorine atom and a partial positive charge (delta plus) at the hydrogen atom. It is this polarity of the bonding that makes hydrogen chloride (a gas) highly soluble in polar solvents such as water, forming hydrochloric acid.