Sample Problem

A water molecule is polar because


(B) is the correct answer. A water molecule is polar because of the electronegativity difference, which creates a slightly more negatively charged oxygen and slightly more positively charged hydrogens. But they are not negative or positive ions (A). Attractions between molecules are a result of charge differences within a water molecule; they are not the cause of the charge shifts (C), and nonpolar molecules do not have charge differences (D).