Physical properties can be observed or measured without changing the composition of matter. Physical properties are used to observe and describe matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others. The three states of matter are: solid, liquid, and gas. The melting point and boiling point are related to changes of the state of matter. An object or substance can be measured or perceived without changing its identity. Physical properties can be intensive or extensive. An intensive property does not depend on the size or amount of matter in the object, while an extensive property does. In addition to extensiveness, properties can also be either isotropic if their values do not depend on the direction of observation or anisotropic otherwise. Physical properties are referred to as observables. They are not modal properties. Solution Physical properties can be observed or measured without changing the composition of matter. Physical properties are used to observe and describe matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others. The three states of matter are: solid, liquid, and gas. The melting point and boiling point are related to changes of the state of matter. An object or substance can be measured or perceived without changing its identity. Physical properties can be intensive or extensive. An intensive property does not depend on the size or amount of matter in the object, while an extensive property does. In addition to extensiveness, properties can also be either isotropic if their values do not depend on the direction of observation or anisotropic otherwise. Physical properties are referred to as observables. They are not modal properties..