Why is the state of matter considered a physical property, even though a substance may change between a solid, liquid, and gas?

Change in which the matter's physical appearance is altered, but composition remains unchanged.

A physical change takes place without any changes in molecular composition. The same element or compound is present before and after the change. The same molecule is present through out the changes. Physical changes are related to physical properties since some measurements require that changes be made. The three main states of matter are: Solid, Liquid, Gas