Polar interactions are determined by what?

• A. The total number of electrons in the molecule
• B. The difference in electronegativity
• C. The size of the molecule
• D. The type of bonding in the molecule

Answer: (B)

Polar interactions come from unequal sharing of electrons in a bond. When two atoms have different electronegativities, electrons are pulled more toward the more electronegative atom, creating a partial negative charge on that atom and a partial positive charge on the other. These partial charges produce dipoles that can attract each other, giving rise to polar interactions like dipole-dipole attractions and hydrogen bonds. The size of the molecule or the total number of electrons doesn’t determine polarity, and while the bonding type matters, it’s the electronegativity difference that sets how polar a bond is and whether the molecule will engage in polar interactions. A bond with no electronegativity difference is nonpolar, regardless of how many electrons are present.