Answer:
They are physical changes.
Step-by-step explanation:
This is because there in no chemical reaction taking place, just a physical change.
A physical change in a change in which the chemical structure of the substance does not change. Ice, water and steam are all the same on a molecular level, thus changing from ice to water or from water to steam are physical changes.
A chemical change is a change in which the chemical structure of the substance undergoes a change, since this does not happen going for A to B or B to C they are not chemical changes.