Answer: Molecules only speed up when given energy, such as heating. When you heat water enough, it will boil and turn into water vapor. So, therefore, if water's molecules speed up, it will go into the gas phase
Explanation: As that liquid water is further heated, it evaporates and becomes a gas—water vapor. These changes between states (melting, freezing, and evaporating) happen because as the temperature either increases or decreases, the molecules in a substance begin to speed up or slow down.
Hope this helps! ^w^