Physical chemistry is the area that deals with the mechanisms, the rate, and the energy transfer that occurs when matter undergoes a change. So the correct option for the given question is option “B”. Whenever there is a change in the state of matter, the physical properties definitely undergo a change. A solid matter will always have a definite shape and volume, while a liquid has a definite volume but no shape. Gases do not have either definite volume or shape. Chemical properties might not be affected, but physical properties are definitely impacted when a matter undergoes change.