What determines bond polarity?

What determines bond polarity?

• A. The number of electrons in the bond
• B. Difference in electronegativity
• C. The molecular geometry
• D. The atomic mass of the atoms

Answer: (B)

Bond polarity comes from how differently two atoms attract bonding electrons. The key idea is electronegativity—the tendency of an atom to pull shared electrons toward itself. When two atoms in a bond have different electronegativities, the more electronegative atom hogs the electron density a bit, creating a dipole with a partial negative charge on that atom and a partial positive charge on the other. That unequal sharing makes the bond polar. If the atoms have similar electronegativities, the electrons are shared more evenly, giving a nonpolar bond. If the difference is very large, the bond can be treated as ionic, with electrons effectively transferred rather than shared. So the deciding factor for bond polarity is the difference in electronegativity, not the number of electrons in the bond, the molecule’s shape, or the atoms’ masses.

Bond polarity comes from how differently two atoms attract bonding electrons. The key idea is electronegativity—the tendency of an atom to pull shared electrons toward itself. When two atoms in a bond have different electronegativities, the more electronegative atom hogs the electron density a bit, creating a dipole with a partial negative charge on that atom and a partial positive charge on the other. That unequal sharing makes the bond polar. If the atoms have similar electronegativities, the electrons are shared more evenly, giving a nonpolar bond. If the difference is very large, the bond can be treated as ionic, with electrons effectively transferred rather than shared. So the deciding factor for bond polarity is the difference in electronegativity, not the number of electrons in the bond, the molecule’s shape, or the atoms’ masses.