4. Water has a high heat of vaporization and boiling point.
Water has the unique property of being able to exist in either of three states: solid, liquid, and gas or steam or water vapor.
The transformation from one to another involves changes in hydrogen bonding and energy levels.
The rule applies that “energy is required for a bond to form, and energy is released when a bond is broken” (Mader 1993).
However, despite its low molecular weight (m.w.= 18.02), water is a liquid at ordinary temperatures and pressure; it does not readily change to ice or steam.