Concept:Boiling is the rapid change of state from liquid to gas at the boiling point.
Explanation:When water is boiling, it continues to absorb heat, but its temperature stays constant.
The added heat energy is used to break the bonds between water molecules.
This causes the liquid water to change into steam, which is gaseous water.
If the boiling water is left open, steam escapes and the mass of liquid decreases over time.
However, the essential and immediate process occurring during boiling is the conversion of water into steam.
The water does not get hotter during boiling, and its mass does not increase.
Answer:D. changes to steam