A physical change in a substance does not change what the substance is. In a chemical change a new substance is formed and energy is either given off or absorbed. For example if a piece of paper is cut into small pieces it is still paper, but if the piece of paper is burned then it is broken up into a different substance. Physical changes can also be reversed but chemical changes cannot.
CAUSES OF PHYSICAL CHANGES
some examples of physical changes with water are:
*Water vapor- it is formed when water is heated to the boiling point or it evaporates.
*Water as a liquid- it is formed when water vapor is cooled or when ice is heated.
*Ice- is formed when water is cooled to the freezing point.