Explain how water molecules differ from
many other molecules.

Water behaves differently from most other chemical compounds. In almost all substances the atoms and molecules move closer together as they get colder. They then solidify. Water, however, attains its greatest density at four degrees Celsius because the water molecules are packed closest together at this temperature.

Explanation:

answer; /// i do believe that the correct answer is (a) boiling

increased stability in the completion of fluorine's outer shell.