Polar Covalent Bonds. A polar covalent bond exists when atoms with different electronegativities share electrons in a covalent bond. Consider the hydrogen chloride (HCl) molecule. Each atom in HCl requires one more electron to form an inert gas electron configuration.
The solubility rules usually go on to say that group IIA sulfides are soluble, but actually group IIA sulfides react with water to make H2S and the group IIA metal hydroxide.
