Question

Water has a higher boiling point than expected because

A. there is so much water vapor in the atmosphere.
B. water molecules are not very massive.
C. hydrogen and oxygen form single covalent bonds.
D. of the strong attractions between polar water molecules

Answer 1

Water has a higher boiling point than expected because of the attractions between molecules.

D. of the strong attractions between polar water molecules

Answer 2

Evaporation occurs when water molecules on the surface gain enough energy to enter the atmosphere. However, stronger intermolecular forces between water molecules cause them to be strongly attracted to each other and to tend to stay in the liquid phase. When the temperature is raised (when heat is applied), more molecules gain the energy needed to escape these intermolecular forces and go into the vapor phase.
Therefore the best answer is D.