In chemistry, a physical change occurs when matter is altered without modifying its basic molecular composition. Some examples of physical changes include boiling or freezing of water, chopping up wood, melting of gold or dissolving salt in water.
Matter is defined in science as anything that occupies space and has mass. It is usually observed and identified through its inherent characteristics, which fall under two categories: physical and chemical properties. Physical changes in matter are closely associated with its physical properties, such as texture, size, shape, odor, density, solubility, boiling point, freezing point and polarity. Matter that has undergone a physical change does not form a new substance. It is only altered through one or several of its physical properties.